TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Hilmas, Greg E.
AU  - Fahrenholtz, William G.
AU  - Brenner, Donald W.
AU  - Maria, Jon‐Paul
AU  - Wolfe, Douglas E.
AU  - Zurek, Eva
AU  - Campilongo, Xiomara
AU  - Curtarolo, Stefano
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16517
AB  - Super-hard (Hf,Mo,Ti,V,W)B2 was synthesized by boro-carbothermal reduction and densified by spark plasma sintering. This composition was produced for the first time as a single-phase ceramic in the present research. The optimized ceramic had a single hexagonal AlB2-type crystalline phase with a grain size of 3.8 µm and homogeneous distribution of the constituent metals. The Vickers hardness exhibited the indentation size effect, increasing from 27 GPa at a load of 9.8 N to as high as 66 GPa at a load of 0.49 N. This is the highest hardness reported to date for high entropy boride ceramics.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W
DO  - 10.1111/jace.19795
UR  - https://hdl.handle.net/21.15107/rcub_dais_16517
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Hilmas, Greg E. and Fahrenholtz, William G. and Brenner, Donald W. and Maria, Jon‐Paul and Wolfe, Douglas E. and Zurek, Eva and Campilongo, Xiomara and Curtarolo, Stefano",
year = "2024",
abstract = "Super-hard (Hf,Mo,Ti,V,W)B2 was synthesized by boro-carbothermal reduction and densified by spark plasma sintering. This composition was produced for the first time as a single-phase ceramic in the present research. The optimized ceramic had a single hexagonal AlB2-type crystalline phase with a grain size of 3.8 µm and homogeneous distribution of the constituent metals. The Vickers hardness exhibited the indentation size effect, increasing from 27 GPa at a load of 9.8 N to as high as 66 GPa at a load of 0.49 N. This is the highest hardness reported to date for high entropy boride ceramics.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W",
doi = "10.1111/jace.19795",
url = "https://hdl.handle.net/21.15107/rcub_dais_16517"
}

Filipović, S., Obradović, N., Hilmas, G. E., Fahrenholtz, W. G., Brenner, D. W., Maria, J., Wolfe, D. E., Zurek, E., Campilongo, X.,& Curtarolo, S.. (2024). A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W. in Journal of the American Ceramic Society
Wiley..
https://doi.org/10.1111/jace.19795
https://hdl.handle.net/21.15107/rcub_dais_16517

Filipović S, Obradović N, Hilmas GE, Fahrenholtz WG, Brenner DW, Maria J, Wolfe DE, Zurek E, Campilongo X, Curtarolo S. A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W. in Journal of the American Ceramic Society. 2024;.
doi:10.1111/jace.19795
https://hdl.handle.net/21.15107/rcub_dais_16517 .

Filipović, Suzana, Obradović, Nina, Hilmas, Greg E., Fahrenholtz, William G., Brenner, Donald W., Maria, Jon‐Paul, Wolfe, Douglas E., Zurek, Eva, Campilongo, Xiomara, Curtarolo, Stefano, "A super‐hard high entropy boride containing Hf, Mo, Ti, V, and W" in Journal of the American Ceramic Society (2024),
https://doi.org/10.1111/jace.19795 .,
https://hdl.handle.net/21.15107/rcub_dais_16517 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Corlett, Cole
AU  - Fahrenholtz, William G.
AU  - Rosenschon, Martin
AU  - Füglein, Ekkehard
AU  - Dojčilović, Radovan
AU  - Tošić, Dragana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir B.
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16516
AB  - Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.
PB  - Wiley
T2  - Journal of Applied Polymer Science
T1  - Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite
SP  - e55040
VL  - 141
IS  - 10
DO  - 10.1002/app.55040
UR  - https://hdl.handle.net/21.15107/rcub_dais_16516
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Corlett, Cole and Fahrenholtz, William G. and Rosenschon, Martin and Füglein, Ekkehard and Dojčilović, Radovan and Tošić, Dragana and Petrović, Jovana and Đorđević, Antonije and Vlahović, Branislav and Pavlović, Vladimir B.",
year = "2024",
abstract = "Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.",
publisher = "Wiley",
journal = "Journal of Applied Polymer Science",
title = "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite",
pages = "e55040",
volume = "141",
number = "10",
doi = "10.1002/app.55040",
url = "https://hdl.handle.net/21.15107/rcub_dais_16516"
}

Filipović, S., Obradović, N., Corlett, C., Fahrenholtz, W. G., Rosenschon, M., Füglein, E., Dojčilović, R., Tošić, D., Petrović, J., Đorđević, A., Vlahović, B.,& Pavlović, V. B.. (2024). Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science
Wiley., 141(10), e55040.
https://doi.org/10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516

Filipović S, Obradović N, Corlett C, Fahrenholtz WG, Rosenschon M, Füglein E, Dojčilović R, Tošić D, Petrović J, Đorđević A, Vlahović B, Pavlović VB. Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science. 2024;141(10):e55040.
doi:10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516 .

Filipović, Suzana, Obradović, Nina, Corlett, Cole, Fahrenholtz, William G., Rosenschon, Martin, Füglein, Ekkehard, Dojčilović, Radovan, Tošić, Dragana, Petrović, Jovana, Đorđević, Antonije, Vlahović, Branislav, Pavlović, Vladimir B., "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite" in Journal of Applied Polymer Science, 141, no. 10 (2024):e55040,
https://doi.org/10.1002/app.55040 .,
https://hdl.handle.net/21.15107/rcub_dais_16516 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Corlett, Cole
AU  - Fahrenholtz, William G.
AU  - Rosenschon, Martin
AU  - Füglein, Ekkehard
AU  - Dojčilović, Radovan
AU  - Tošić, Dragana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
AU  - Vlahović, Branislav
AU  - Pavlović, Vladimir B.
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16243
AB  - Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.
PB  - Wiley
T2  - Journal of Applied Polymer Science
T1  - Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite
SP  - e55040
VL  - 141
IS  - 10
DO  - 10.1002/app.55040
UR  - https://hdl.handle.net/21.15107/rcub_dais_16516
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Corlett, Cole and Fahrenholtz, William G. and Rosenschon, Martin and Füglein, Ekkehard and Dojčilović, Radovan and Tošić, Dragana and Petrović, Jovana and Đorđević, Antonije and Vlahović, Branislav and Pavlović, Vladimir B.",
year = "2024",
abstract = "Ceramic/polymer composites can be chemically stable, mechanically strong, and flexible, which make them candidates for electric devices, such as pressure or temperature sensors, energy storage or harvesting devices, actuators, and so forth. Depending on the application, various electrical properties are of importance. Polymers usually have low dielectric permittivity, but increased dielectric permittivity can be achieved by the addition of the ceramic fillers with high dielectric constant. With the aim to enhance dielectric properties of the composite without loss of flexibility, 5 wt% of BaTiO3-Fe2O3 powder was added into a polyvinylidene fluoride matrix. The powder was prepared by different synthesis conditions to produce core/shell structures. The effect of the phase composition and morphology of the BaTiO3-Fe2O3 core/shell filler on the structure and lattice dynamics of the polymer composites was investigated. Based on the results of the thermal analysis, various parameters of ceramic/polymer composites were determined. Differences in the phase composition and morphology of the filler have an influence on the formation of various polyvinylidene fluoride allomorphs and the degree of crystallinity. Furthermore, the dielectric performances of pure polyvinylidene fluoride and the polymer/ceramic composites were measured.",
publisher = "Wiley",
journal = "Journal of Applied Polymer Science",
title = "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite",
pages = "e55040",
volume = "141",
number = "10",
doi = "10.1002/app.55040",
url = "https://hdl.handle.net/21.15107/rcub_dais_16516"
}

Filipović, S., Obradović, N., Corlett, C., Fahrenholtz, W. G., Rosenschon, M., Füglein, E., Dojčilović, R., Tošić, D., Petrović, J., Đorđević, A., Vlahović, B.,& Pavlović, V. B.. (2024). Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science
Wiley., 141(10), e55040.
https://doi.org/10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516

Filipović S, Obradović N, Corlett C, Fahrenholtz WG, Rosenschon M, Füglein E, Dojčilović R, Tošić D, Petrović J, Đorđević A, Vlahović B, Pavlović VB. Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite. in Journal of Applied Polymer Science. 2024;141(10):e55040.
doi:10.1002/app.55040
https://hdl.handle.net/21.15107/rcub_dais_16516 .

Filipović, Suzana, Obradović, Nina, Corlett, Cole, Fahrenholtz, William G., Rosenschon, Martin, Füglein, Ekkehard, Dojčilović, Radovan, Tošić, Dragana, Petrović, Jovana, Đorđević, Antonije, Vlahović, Branislav, Pavlović, Vladimir B., "Effect of the filler morphology on the crystallization behavior and dielectric properties of the polyvinylidene fluoride‐based composite" in Journal of Applied Polymer Science, 141, no. 10 (2024):e55040,
https://doi.org/10.1002/app.55040 .,
https://hdl.handle.net/21.15107/rcub_dais_16516 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
AU  - Obradović, Nina
AU  - Curtarolo, Stefano
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16386
AB  - Dual phase high entropy ceramics are attractive due to potential synergetic effects of the constituents on mechanical properties and thermal stability. In this research, dense, dual phase (Hf,Mo,Ti,W,Z) B2-(Hf.Mo.Ti.W,Zr)C powder was synthesized by varying the contents of the transition metals in the final product. The co-synthesis method was used to obtain boride and carbide constituents by boro/ carbothermal reduction of mixtures of oxides and appropriate amounts of carbon black and B4C. Solid solution formation and densification of the reacted powders were done utilizing two step spark plasma sintering or hot pressing processes. Phase compositions of the produced ceramics were identified by x-ray diffraction while chemical compositions were measured using energy dispersive spectroscopy. The final microstructures showed submicron grains due to pining effect of the two phases. Investigation of the mechanical properties showed increasing in Vickers hardness values s up to 48.6 2.2 GPa for applied load of 0.49N for compositions with optimized elemental contents. Room temperature strength was also measured.
PB  - American Ceramic Society
C3  - Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
T1  - Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics
UR  - https://hdl.handle.net/21.15107/rcub_dais_16386
ER  - 

@conference{
author = "Filipović, Suzana and Hilmas, Gregory E. and Fahrenholtz, William G. and Obradović, Nina and Curtarolo, Stefano",
year = "2024",
abstract = "Dual phase high entropy ceramics are attractive due to potential synergetic effects of the constituents on mechanical properties and thermal stability. In this research, dense, dual phase (Hf,Mo,Ti,W,Z) B2-(Hf.Mo.Ti.W,Zr)C powder was synthesized by varying the contents of the transition metals in the final product. The co-synthesis method was used to obtain boride and carbide constituents by boro/ carbothermal reduction of mixtures of oxides and appropriate amounts of carbon black and B4C. Solid solution formation and densification of the reacted powders were done utilizing two step spark plasma sintering or hot pressing processes. Phase compositions of the produced ceramics were identified by x-ray diffraction while chemical compositions were measured using energy dispersive spectroscopy. The final microstructures showed submicron grains due to pining effect of the two phases. Investigation of the mechanical properties showed increasing in Vickers hardness values s up to 48.6 2.2 GPa for applied load of 0.49N for compositions with optimized elemental contents. Room temperature strength was also measured.",
publisher = "American Ceramic Society",
journal = "Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida",
title = "Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics",
url = "https://hdl.handle.net/21.15107/rcub_dais_16386"
}

Filipović, S., Hilmas, G. E., Fahrenholtz, W. G., Obradović, N.,& Curtarolo, S.. (2024). Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics. in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida
American Ceramic Society..
https://hdl.handle.net/21.15107/rcub_dais_16386

Filipović S, Hilmas GE, Fahrenholtz WG, Obradović N, Curtarolo S. Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics. in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida. 2024;.
https://hdl.handle.net/21.15107/rcub_dais_16386 .

Filipović, Suzana, Hilmas, Gregory E., Fahrenholtz, William G., Obradović, Nina, Curtarolo, Stefano, "Synthesis and Properties of (Hf,Mo,Ti,W,Zr)B2-(Hf,Mo,Ti,W,Z)C Dual Phase Ceramics" in Abstract Book / 48th International Conference & Exposition on Advanced Ceramics and Composites, January 28–February 2, 2024, Daytona Beach, Florida (2024),
https://hdl.handle.net/21.15107/rcub_dais_16386 .

TY  - JOUR
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Fahrenholtz, William
AU  - Smith, Steven
AU  - Mirković, Miljana M.
AU  - Peleš Tadić, Adriana
AU  - Petrović, Jovana
AU  - Đorđević, Antonije
PY  - 2024
UR  - https://dais.sanu.ac.rs/123456789/16383
AB  - Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.
T2  - Ceramics International
T1  - Spark plasma sintering of magnesium titanate ceramics
DO  - 10.1016/j.ceramint.2024.02.004
UR  - https://hdl.handle.net/21.15107/rcub_dais_16383
ER  - 

@article{
author = "Filipović, Suzana and Obradović, Nina and Fahrenholtz, William and Smith, Steven and Mirković, Miljana M. and Peleš Tadić, Adriana and Petrović, Jovana and Đorđević, Antonije",
year = "2024",
abstract = "Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was observed for specimens prepared with longer milling times and attributed to the coefficient of thermal expansion (CTE) mismatch dominantly due to the anisotropic crystal structure of MgTiO3 phase. The sample milled for 15 min showed the highest Vickers hardness due to less or no microcracking and nearly full density. The dielectric measurements in the range of 10 Hz–250 MHz demonstrated extremely high dielectric permittivity, as high as 104 at 1 kHz. An increase in loss tangents was observed due to oxygen vacancy formation, which was promoted by the vacuum environment during SPS. Oxygen vacancy-related dielectric relaxation was also detected and explained.",
journal = "Ceramics International",
title = "Spark plasma sintering of magnesium titanate ceramics",
doi = "10.1016/j.ceramint.2024.02.004",
url = "https://hdl.handle.net/21.15107/rcub_dais_16383"
}

Filipović, S., Obradović, N., Fahrenholtz, W., Smith, S., Mirković, M. M., Peleš Tadić, A., Petrović, J.,& Đorđević, A.. (2024). Spark plasma sintering of magnesium titanate ceramics. in Ceramics International.
https://doi.org/10.1016/j.ceramint.2024.02.004
https://hdl.handle.net/21.15107/rcub_dais_16383

Filipović S, Obradović N, Fahrenholtz W, Smith S, Mirković MM, Peleš Tadić A, Petrović J, Đorđević A. Spark plasma sintering of magnesium titanate ceramics. in Ceramics International. 2024;.
doi:10.1016/j.ceramint.2024.02.004
https://hdl.handle.net/21.15107/rcub_dais_16383 .

Filipović, Suzana, Obradović, Nina, Fahrenholtz, William, Smith, Steven, Mirković, Miljana M., Peleš Tadić, Adriana, Petrović, Jovana, Đorđević, Antonije, "Spark plasma sintering of magnesium titanate ceramics" in Ceramics International (2024),
https://doi.org/10.1016/j.ceramint.2024.02.004 .,
https://hdl.handle.net/21.15107/rcub_dais_16383 .

TY  - JOUR
AU  - Corlett, Cole A.
AU  - Obradović, Nina
AU  - Watts, Jeremy L.
AU  - Bohannan, Eric W.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14708
AB  - The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers’ hardness values were at least 10 GPa for all compositions. The cations present in the high-entropy spinel appear to have a stabilizing effect that led to nearly normal site occupancy compared to full cation inversion behavior of nickel aluminate spinel. This is the first report that compares cation site occupancy of a high-entropy spinel to conventional spinel ceramics.
PB  - Informa UK Limited
T2  - Journal of Asian Ceramic Societies
T1  - Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel
SP  - 1
SP  - 330
EP  - 8
EP  - 337
VL  - 11
IS  - 3
DO  - 10.1080/21870764.2023.2227535
UR  - https://hdl.handle.net/21.15107/rcub_dais_14708
ER  - 

@article{
author = "Corlett, Cole A. and Obradović, Nina and Watts, Jeremy L. and Bohannan, Eric W. and Fahrenholtz, William G.",
year = "2023",
abstract = "The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form a single phase, but analysis of X-ray diffraction patterns revealed differences in cation site occupancy with the high-entropy spinel being nearly fully normal. Densification behavior was investigated and showed that fully dense ceramics could be produced by hot pressing at temperatures as low as 1375°C for all compositions. Vickers’ hardness values were at least 10 GPa for all compositions. The cations present in the high-entropy spinel appear to have a stabilizing effect that led to nearly normal site occupancy compared to full cation inversion behavior of nickel aluminate spinel. This is the first report that compares cation site occupancy of a high-entropy spinel to conventional spinel ceramics.",
publisher = "Informa UK Limited",
journal = "Journal of Asian Ceramic Societies",
title = "Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel",
pages = "1-330-8-337",
volume = "11",
number = "3",
doi = "10.1080/21870764.2023.2227535",
url = "https://hdl.handle.net/21.15107/rcub_dais_14708"
}

Corlett, C. A., Obradović, N., Watts, J. L., Bohannan, E. W.,& Fahrenholtz, W. G.. (2023). Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel. in Journal of Asian Ceramic Societies
Informa UK Limited., 11(3), 1-8.
https://doi.org/10.1080/21870764.2023.2227535
https://hdl.handle.net/21.15107/rcub_dais_14708

Corlett CA, Obradović N, Watts JL, Bohannan EW, Fahrenholtz WG. Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel. in Journal of Asian Ceramic Societies. 2023;11(3):1-8.
doi:10.1080/21870764.2023.2227535
https://hdl.handle.net/21.15107/rcub_dais_14708 .

Corlett, Cole A., Obradović, Nina, Watts, Jeremy L., Bohannan, Eric W., Fahrenholtz, William G., "Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al2O4 spinel" in Journal of Asian Ceramic Societies, 11, no. 3 (2023):1-8,
https://doi.org/10.1080/21870764.2023.2227535 .,
https://hdl.handle.net/21.15107/rcub_dais_14708 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, Miljana
AU  - Kosanović, Darko
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14877
AB  - Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.
PB  - Elsevier BV
T2  - Journal of the European Ceramic Society
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - 7306
EP  - 7313
VL  - 43
DO  - 10.1016/j.jeurceramsoc.2023.08.007
UR  - https://hdl.handle.net/21.15107/rcub_dais_14877
ER  - 

@article{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, Miljana and Kosanović, Darko and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.",
publisher = "Elsevier BV",
journal = "Journal of the European Ceramic Society",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "7306-7313",
volume = "43",
doi = "10.1016/j.jeurceramsoc.2023.08.007",
url = "https://hdl.handle.net/21.15107/rcub_dais_14877"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Rogan, J.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society
Elsevier BV., 43, 7306-7313.
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14877

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Rogan J, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society. 2023;43:7306-7313.
doi:10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14877 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, Miljana, Kosanović, Darko, Rogan, Jelena, Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Journal of the European Ceramic Society, 43 (2023):7306-7313,
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007 .,
https://hdl.handle.net/21.15107/rcub_dais_14877 .

TY  - CONF
AU  - Peleš Tadić, Adriana
AU  - Vuković, George
AU  - Kojović, Aleksandar
AU  - Stojanović, Dušica
AU  - Vlahović, Branislav
AU  - Milosavljević, Nataša
AU  - Obradović, Nina
AU  - Pavlović, Vladimir B.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14969
AB  - Barium titanate (BaTiO3) and polyvinylidene fluoride (PVDF) based multifunctional materials are attracting a great scientific interest due to their excellent piezoelectric, pyroelectric and ferroelectric properties. These materials undergo controlled transformations through physical interactions and respond to environmental stimuli, such as temperature, pressure, electric and magnetic fields. Their properties strongly depend on synthesis procedures and obtained microstructures. This include intergranular contact surfaces of BaTiO3 based materials, as well as, porous structure and cross-linking patterns of PVDF prepared by electrospinning. It has been found that these microstructures can have fractal structure and that the fractal analysis can be used as a powerful tool for describing structural and functional properties of these materials. Having this in mind, in this research we have used different fractal methods for the reconstructions of various BaTiO3 and PVDF microstructure morphologies. Fractal analysis has been performed by using scanning electron microscope micrographs and computational modeling tools. Fractal dimension of irregular morphologies which exhibit fractal regularity were determined by using box-counting method. This method enables the analysis of self-similar microstructure morphologies by quantifying the rate at which an object's geometrical details develop at increasingly fine scales. Theory of Iterated Function Systems and Voronoi tessellation, have been used for modeling BaTiO3 random microstructures and PVDF porous structures. A python algorithm was created to determine the distribution of pore areas in SEM micrographs. Algorithm’s distribution of calculated pore surface areas was compared with measured pore surface areas and fractal reconstructions of different morphologies and their connection with functional properties were analyzed.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Fractal analysis and microstructure development of BaTiO3 and PVDF based multifunctional materials
SP  - 46
UR  - https://hdl.handle.net/21.15107/rcub_dais_14969
ER  - 

@conference{
author = "Peleš Tadić, Adriana and Vuković, George and Kojović, Aleksandar and Stojanović, Dušica and Vlahović, Branislav and Milosavljević, Nataša and Obradović, Nina and Pavlović, Vladimir B.",
year = "2023",
abstract = "Barium titanate (BaTiO3) and polyvinylidene fluoride (PVDF) based multifunctional materials are attracting a great scientific interest due to their excellent piezoelectric, pyroelectric and ferroelectric properties. These materials undergo controlled transformations through physical interactions and respond to environmental stimuli, such as temperature, pressure, electric and magnetic fields. Their properties strongly depend on synthesis procedures and obtained microstructures. This include intergranular contact surfaces of BaTiO3 based materials, as well as, porous structure and cross-linking patterns of PVDF prepared by electrospinning. It has been found that these microstructures can have fractal structure and that the fractal analysis can be used as a powerful tool for describing structural and functional properties of these materials. Having this in mind, in this research we have used different fractal methods for the reconstructions of various BaTiO3 and PVDF microstructure morphologies. Fractal analysis has been performed by using scanning electron microscope micrographs and computational modeling tools. Fractal dimension of irregular morphologies which exhibit fractal regularity were determined by using box-counting method. This method enables the analysis of self-similar microstructure morphologies by quantifying the rate at which an object's geometrical details develop at increasingly fine scales. Theory of Iterated Function Systems and Voronoi tessellation, have been used for modeling BaTiO3 random microstructures and PVDF porous structures. A python algorithm was created to determine the distribution of pore areas in SEM micrographs. Algorithm’s distribution of calculated pore surface areas was compared with measured pore surface areas and fractal reconstructions of different morphologies and their connection with functional properties were analyzed.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Fractal analysis and microstructure development of BaTiO3 and PVDF based multifunctional materials",
pages = "46",
url = "https://hdl.handle.net/21.15107/rcub_dais_14969"
}

Peleš Tadić, A., Vuković, G., Kojović, A., Stojanović, D., Vlahović, B., Milosavljević, N., Obradović, N.,& Pavlović, V. B.. (2023). Fractal analysis and microstructure development of BaTiO3 and PVDF based multifunctional materials. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 46.
https://hdl.handle.net/21.15107/rcub_dais_14969

Peleš Tadić A, Vuković G, Kojović A, Stojanović D, Vlahović B, Milosavljević N, Obradović N, Pavlović VB. Fractal analysis and microstructure development of BaTiO3 and PVDF based multifunctional materials. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:46.
https://hdl.handle.net/21.15107/rcub_dais_14969 .

Peleš Tadić, Adriana, Vuković, George, Kojović, Aleksandar, Stojanović, Dušica, Vlahović, Branislav, Milosavljević, Nataša, Obradović, Nina, Pavlović, Vladimir B., "Fractal analysis and microstructure development of BaTiO3 and PVDF based multifunctional materials" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):46,
https://hdl.handle.net/21.15107/rcub_dais_14969 .

TY  - JOUR
AU  - Stanfield, Austin D.
AU  - Smith, Steven M.
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Buljak, Vladimir
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15143
AB  - Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - Final‐stage densification kinetics of direct current–sintered ZrB2
SP  - 5654
EP  - 5661
VL  - 106
IS  - 10
DO  - 10.1111/jace.19212
UR  - https://hdl.handle.net/21.15107/rcub_dais_15143
ER  - 

@article{
author = "Stanfield, Austin D. and Smith, Steven M. and Filipović, Suzana and Obradović, Nina and Buljak, Vladimir and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "Final‐stage densification kinetics of direct current–sintered ZrB2",
pages = "5654-5661",
volume = "106",
number = "10",
doi = "10.1111/jace.19212",
url = "https://hdl.handle.net/21.15107/rcub_dais_15143"
}

Stanfield, A. D., Smith, S. M., Filipović, S., Obradović, N., Buljak, V., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society
Wiley., 106(10), 5654-5661.
https://doi.org/10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15143

Stanfield AD, Smith SM, Filipović S, Obradović N, Buljak V, Hilmas GE, Fahrenholtz WG. Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society. 2023;106(10):5654-5661.
doi:10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15143 .

Stanfield, Austin D., Smith, Steven M., Filipović, Suzana, Obradović, Nina, Buljak, Vladimir, Hilmas, Gregory E., Fahrenholtz, William G., "Final‐stage densification kinetics of direct current–sintered ZrB2" in Journal of the American Ceramic Society, 106, no. 10 (2023):5654-5661,
https://doi.org/10.1111/jace.19212 .,
https://hdl.handle.net/21.15107/rcub_dais_15143 .

TY  - JOUR
AU  - Stanfield, Austin D.
AU  - Smith, Steven M.
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Buljak, Vladimir
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15196
AB  - Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.
PB  - Wiley
T2  - Journal of the American Ceramic Society
T1  - Final‐stage densification kinetics of direct current–sintered ZrB2
SP  - 5654
EP  - 5661
VL  - 106
IS  - 10
DO  - 10.1111/jace.19212
UR  - https://hdl.handle.net/21.15107/rcub_dais_15196
ER  - 

@article{
author = "Stanfield, Austin D. and Smith, Steven M. and Filipović, Suzana and Obradović, Nina and Buljak, Vladimir and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "Final-stage sintering was analyzed for nominally phase pure zirconium diboride synthesized by borothermal reduction of high-purity ZrO2. Analysis was conducted on ZrB2 ceramics with relative densities greater than 90% using the Nabarro–Herring stress–directed vacancy diffusion model. Temperatures of 1900°C or above and an applied uniaxial pressure of 50 MPa were required to fully densify ZrB2 ceramics by direct current sintering. Ram travel data were collected and used to determine the relative density of the specimens during sintering. Specimens sintered between 1900 and 2100°C achieved relative densities greater than 97%, whereas specimens sintered below 1900°C failed to reach the final stage of sintering. The average grain size ranged from 1.0 to 14.7 μm. The activation energy was calculated from the slope of an Arrhenius plot that used the Kalish equation. The activation energy was 162 ± 34 kJ/mol, which is consistent with the activation energy for dislocation movement in ZrB2. The diffusion coefficients for dislocation motion that controls densification were 5.1 × 10−6 cm2/s at 1900°C and 5.1 × 10−5 cm2/s at 2100°C, as calculated from activation energy and average grain sizes. This study provides evidence that the dominant mechanism for final-stage sintering of ZrB2 ceramics is dislocation motion.",
publisher = "Wiley",
journal = "Journal of the American Ceramic Society",
title = "Final‐stage densification kinetics of direct current–sintered ZrB2",
pages = "5654-5661",
volume = "106",
number = "10",
doi = "10.1111/jace.19212",
url = "https://hdl.handle.net/21.15107/rcub_dais_15196"
}

Stanfield, A. D., Smith, S. M., Filipović, S., Obradović, N., Buljak, V., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society
Wiley., 106(10), 5654-5661.
https://doi.org/10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15196

Stanfield AD, Smith SM, Filipović S, Obradović N, Buljak V, Hilmas GE, Fahrenholtz WG. Final‐stage densification kinetics of direct current–sintered ZrB2. in Journal of the American Ceramic Society. 2023;106(10):5654-5661.
doi:10.1111/jace.19212
https://hdl.handle.net/21.15107/rcub_dais_15196 .

Stanfield, Austin D., Smith, Steven M., Filipović, Suzana, Obradović, Nina, Buljak, Vladimir, Hilmas, Gregory E., Fahrenholtz, William G., "Final‐stage densification kinetics of direct current–sintered ZrB2" in Journal of the American Ceramic Society, 106, no. 10 (2023):5654-5661,
https://doi.org/10.1111/jace.19212 .,
https://hdl.handle.net/21.15107/rcub_dais_15196 .

TY  - JOUR
AU  - Peleš Tadić, Adriana
AU  - Vuković, George
AU  - Kojović, Aleksandar
AU  - Stojanović, Dušica
AU  - Vlahović, Branislav
AU  - Obradović, Nina
AU  - Pavlović, Vladimir
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16173
AB  - Polyvinylidene fluoride (PVDF) is a novel gel polymer electrolyte alternative which can reduce the risk of irreversible failure in lithium-ion batteries (LIB) [1]. PVDF matrix structures which exhibit inter-crosslinking networks have previously demonstrated favorable thermal and mechanical properties for LIB applications [2]. PVDF based multifunctional material is attracting a great scientific interest due to its excellent piezoelectric, pyroelectric and ferroelectric properties. Such as, its properties strongly depend on synthesis procedures and obtained microstructures. In this research, porous structure and cross-linking patterns of PVDF were prepared by electrospinning method and it has been found that these microstructures can have fractal structure. Fractal analysis can be used as a powerful tool for describing structural and functional properties of these this material. Because of that, in this research we have used different fractal methods for the reconstructions of various PVDF microstructure morphologies. Fractal analysis has been performed by using scanning electron microscope micrographs and computational modeling tools. Theory of Iterated Function Systems and Voronoi tessellation, have been used for modeling PVDF porous structures. A Python algorithm was created to determine the distribution of pore areas in SEM micrographs. Algorithm’s distribution of calculated pore surface areas were compared with measured pore surface areas and fractal reconstructions of different morphologies and their connection with functional properties were analyzed.
PB  - Belgrade : ETRAN
T2  - Science of Sintering
T1  - Fractal analysis and microstructure development PVDF based multifunctional material
DO  - 10.2298/SOS231031061P
UR  - https://hdl.handle.net/21.15107/rcub_dais_16173
ER  - 

@article{
author = "Peleš Tadić, Adriana and Vuković, George and Kojović, Aleksandar and Stojanović, Dušica and Vlahović, Branislav and Obradović, Nina and Pavlović, Vladimir",
year = "2023",
abstract = "Polyvinylidene fluoride (PVDF) is a novel gel polymer electrolyte alternative which can reduce the risk of irreversible failure in lithium-ion batteries (LIB) [1]. PVDF matrix structures which exhibit inter-crosslinking networks have previously demonstrated favorable thermal and mechanical properties for LIB applications [2]. PVDF based multifunctional material is attracting a great scientific interest due to its excellent piezoelectric, pyroelectric and ferroelectric properties. Such as, its properties strongly depend on synthesis procedures and obtained microstructures. In this research, porous structure and cross-linking patterns of PVDF were prepared by electrospinning method and it has been found that these microstructures can have fractal structure. Fractal analysis can be used as a powerful tool for describing structural and functional properties of these this material. Because of that, in this research we have used different fractal methods for the reconstructions of various PVDF microstructure morphologies. Fractal analysis has been performed by using scanning electron microscope micrographs and computational modeling tools. Theory of Iterated Function Systems and Voronoi tessellation, have been used for modeling PVDF porous structures. A Python algorithm was created to determine the distribution of pore areas in SEM micrographs. Algorithm’s distribution of calculated pore surface areas were compared with measured pore surface areas and fractal reconstructions of different morphologies and their connection with functional properties were analyzed.",
publisher = "Belgrade : ETRAN",
journal = "Science of Sintering",
title = "Fractal analysis and microstructure development PVDF based multifunctional material",
doi = "10.2298/SOS231031061P",
url = "https://hdl.handle.net/21.15107/rcub_dais_16173"
}

Peleš Tadić, A., Vuković, G., Kojović, A., Stojanović, D., Vlahović, B., Obradović, N.,& Pavlović, V.. (2023). Fractal analysis and microstructure development PVDF based multifunctional material. in Science of Sintering
Belgrade : ETRAN..
https://doi.org/10.2298/SOS231031061P
https://hdl.handle.net/21.15107/rcub_dais_16173

Peleš Tadić A, Vuković G, Kojović A, Stojanović D, Vlahović B, Obradović N, Pavlović V. Fractal analysis and microstructure development PVDF based multifunctional material. in Science of Sintering. 2023;.
doi:10.2298/SOS231031061P
https://hdl.handle.net/21.15107/rcub_dais_16173 .

Peleš Tadić, Adriana, Vuković, George, Kojović, Aleksandar, Stojanović, Dušica, Vlahović, Branislav, Obradović, Nina, Pavlović, Vladimir, "Fractal analysis and microstructure development PVDF based multifunctional material" in Science of Sintering (2023),
https://doi.org/10.2298/SOS231031061P .,
https://hdl.handle.net/21.15107/rcub_dais_16173 .

TY  - JOUR
AU  - Nedeljković, Borivoje
AU  - Pavlović, Vladimir B.
AU  - Obradović, Nina
AU  - Mitrović, Nebojša S.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16179
AB  - The structural properties of a magnetically semi-hard near equiatomic FeCo-2wt%V (FeCoV) alloy produced by Powder Injection Moulding (PIM) (option by fine metal powder - Metal Injection Moulding (MIM) technology) were investigated in this paper. Starting granulate was prepared by mixing FeCoV powder with a low-viscosity binder. After injection, the green samples were first treated with a solvent and then thermally with the same aim of removing the binder. MIM technology was completed by high-temperature sintering for 3.5 hours at temperatures from 1370 OC to 1460 OC in a hydrogen atmosphere, which provides the necessary magnetic and mechanical characteristics. The influence of sintering temperature was investigated concerning the aspects of the processes of structural transformation by the methods of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The appearance of an intense diffraction peak of the α'-FeCo phase (crystal structure type B2) was registered for all investigated samples. Structural parameters particle size Dmax, Feret X, and Feret Y exhibit constant increase with increase of sintering temperature.
PB  - Belgrade : ETRAN
T2  - Science of Sintering
T1  - Structural features of near equiatomic FeCo-2V semi-hard magnetic alloy prepared by MIM technology
VL  - 55
DO  - 10.2298/SOS231024055N
UR  - https://hdl.handle.net/21.15107/rcub_dais_16179
ER  - 

@article{
author = "Nedeljković, Borivoje and Pavlović, Vladimir B. and Obradović, Nina and Mitrović, Nebojša S.",
year = "2023",
abstract = "The structural properties of a magnetically semi-hard near equiatomic FeCo-2wt%V (FeCoV) alloy produced by Powder Injection Moulding (PIM) (option by fine metal powder - Metal Injection Moulding (MIM) technology) were investigated in this paper. Starting granulate was prepared by mixing FeCoV powder with a low-viscosity binder. After injection, the green samples were first treated with a solvent and then thermally with the same aim of removing the binder. MIM technology was completed by high-temperature sintering for 3.5 hours at temperatures from 1370 OC to 1460 OC in a hydrogen atmosphere, which provides the necessary magnetic and mechanical characteristics. The influence of sintering temperature was investigated concerning the aspects of the processes of structural transformation by the methods of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The appearance of an intense diffraction peak of the α'-FeCo phase (crystal structure type B2) was registered for all investigated samples. Structural parameters particle size Dmax, Feret X, and Feret Y exhibit constant increase with increase of sintering temperature.",
publisher = "Belgrade : ETRAN",
journal = "Science of Sintering",
title = "Structural features of near equiatomic FeCo-2V semi-hard magnetic alloy prepared by MIM technology",
volume = "55",
doi = "10.2298/SOS231024055N",
url = "https://hdl.handle.net/21.15107/rcub_dais_16179"
}

Nedeljković, B., Pavlović, V. B., Obradović, N.,& Mitrović, N. S.. (2023). Structural features of near equiatomic FeCo-2V semi-hard magnetic alloy prepared by MIM technology. in Science of Sintering
Belgrade : ETRAN., 55.
https://doi.org/10.2298/SOS231024055N
https://hdl.handle.net/21.15107/rcub_dais_16179

Nedeljković B, Pavlović VB, Obradović N, Mitrović NS. Structural features of near equiatomic FeCo-2V semi-hard magnetic alloy prepared by MIM technology. in Science of Sintering. 2023;55.
doi:10.2298/SOS231024055N
https://hdl.handle.net/21.15107/rcub_dais_16179 .

Nedeljković, Borivoje, Pavlović, Vladimir B., Obradović, Nina, Mitrović, Nebojša S., "Structural features of near equiatomic FeCo-2V semi-hard magnetic alloy prepared by MIM technology" in Science of Sintering, 55 (2023),
https://doi.org/10.2298/SOS231024055N .,
https://hdl.handle.net/21.15107/rcub_dais_16179 .

TY  - JOUR
AU  - Aleksić, Stanko
AU  - Obradović, Nina
AU  - Mitrović, Nebojša S.
AU  - Luković, Miloljub D.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16180
AB  - A powder of Cu0.2Ni0.5Zn1.0 Mn1.3O4 composition for custom thermistor was prepared by using the respective mixture of metal oxides and solid state reaction at 1000 °C/4h in air. The obtained thermistor powder was milled in the planetary ball mill and agate mill for a prolonged time to achieve submicron powder. The prepared thermistor powder was further characterized by using XRD and SEM techniques. After that, the thermistor powder was pressed into small disc-shaped samples and sintered at 1150 °C/2h. The sintered samples were also characterized by using XRD and SEM. The main electrical properties such as nominal resistance R and thermistor exponential factor B were measured in the climatic test chamber. After that, the thick film paste was prepared using the same powder, an organic vehicle and a glass frit. The paste was printed on alumina substrate, dried at 150 °C /30 min and sintered in air at 850 °C /10 min in a hybrid conveyor furnace. Planar electrodes were printed on the sintered NTC thermistor layer using PdAg thick film paste. The electric properties of the sintered thick film thermistor were also measured in the climatic test chamber. The obtained results were used for development of novel self-heating thermistor applications.
PB  - Belgrade : ETRAN
T2  - Science of Sintering
T1  - Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4
DO  - 10.2298/SOS230608036A
UR  - https://hdl.handle.net/21.15107/rcub_dais_16180
ER  - 

@article{
author = "Aleksić, Stanko and Obradović, Nina and Mitrović, Nebojša S. and Luković, Miloljub D.",
year = "2023",
abstract = "A powder of Cu0.2Ni0.5Zn1.0 Mn1.3O4 composition for custom thermistor was prepared by using the respective mixture of metal oxides and solid state reaction at 1000 °C/4h in air. The obtained thermistor powder was milled in the planetary ball mill and agate mill for a prolonged time to achieve submicron powder. The prepared thermistor powder was further characterized by using XRD and SEM techniques. After that, the thermistor powder was pressed into small disc-shaped samples and sintered at 1150 °C/2h. The sintered samples were also characterized by using XRD and SEM. The main electrical properties such as nominal resistance R and thermistor exponential factor B were measured in the climatic test chamber. After that, the thick film paste was prepared using the same powder, an organic vehicle and a glass frit. The paste was printed on alumina substrate, dried at 150 °C /30 min and sintered in air at 850 °C /10 min in a hybrid conveyor furnace. Planar electrodes were printed on the sintered NTC thermistor layer using PdAg thick film paste. The electric properties of the sintered thick film thermistor were also measured in the climatic test chamber. The obtained results were used for development of novel self-heating thermistor applications.",
publisher = "Belgrade : ETRAN",
journal = "Science of Sintering",
title = "Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4",
doi = "10.2298/SOS230608036A",
url = "https://hdl.handle.net/21.15107/rcub_dais_16180"
}

Aleksić, S., Obradović, N., Mitrović, N. S.,& Luković, M. D.. (2023). Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4. in Science of Sintering
Belgrade : ETRAN..
https://doi.org/10.2298/SOS230608036A
https://hdl.handle.net/21.15107/rcub_dais_16180

Aleksić S, Obradović N, Mitrović NS, Luković MD. Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4. in Science of Sintering. 2023;.
doi:10.2298/SOS230608036A
https://hdl.handle.net/21.15107/rcub_dais_16180 .

Aleksić, Stanko, Obradović, Nina, Mitrović, Nebojša S., Luković, Miloljub D., "Characterization of NTC thick film thermistor paste Cu0.2Ni0.5Zn1.0Mn1.3O4" in Science of Sintering (2023),
https://doi.org/10.2298/SOS230608036A .,
https://hdl.handle.net/21.15107/rcub_dais_16180 .

TY  - CONF
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Feng, Lun
AU  - Mirković, M.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16181
AB  - Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. Milled powders were densified by spark plasma sintering at 2000 °C. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 minutes. Microstructure analysis showed that grain size was less than 2 microns for powder milled for 15 minutes. Based on densification data and impurities level, milling time of
15 minutes appears to give the best balance of particle size reduction to promote densification while minimizing impurities level.
PB  - American Ceramic Society
C3  - Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - ICACC-S18-025-2023
SP  - 117
EP  - 118
UR  - https://hdl.handle.net/21.15107/rcub_dais_16181
ER  - 

@conference{
author = "Obradović, Nina and Filipović, Suzana and Feng, Lun and Mirković, M. and Fahrenholtz, William G.",
year = "2023",
abstract = "Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. Milled powders were densified by spark plasma sintering at 2000 °C. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 minutes. Microstructure analysis showed that grain size was less than 2 microns for powder milled for 15 minutes. Based on densification data and impurities level, milling time of
15 minutes appears to give the best balance of particle size reduction to promote densification while minimizing impurities level.",
publisher = "American Ceramic Society",
journal = "Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "ICACC-S18-025-2023-117-118",
url = "https://hdl.handle.net/21.15107/rcub_dais_16181"
}

Obradović, N., Filipović, S., Feng, L., Mirković, M.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida
American Ceramic Society., ICACC-S18-025-2023-118.
https://hdl.handle.net/21.15107/rcub_dais_16181

Obradović N, Filipović S, Feng L, Mirković M, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida. 2023;:ICACC-S18-025-2023-118.
https://hdl.handle.net/21.15107/rcub_dais_16181 .

Obradović, Nina, Filipović, Suzana, Feng, Lun, Mirković, M., Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Abstract Book / 47th International Conference & Exposition on Advanced Ceramics and Composites, January 22–27, 2023, Daytona Beach, Florida (2023):ICACC-S18-025-2023-118,
https://hdl.handle.net/21.15107/rcub_dais_16181 .

TY  - CONF
AU  - Dinkić, J.
AU  - Lević, S. M.
AU  - Nedović, Viktor
AU  - Obradović, Nina
AU  - Đorđević, Antonije
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16182
AB  - Suspended viable cells significantly influence the relative complex permittivity (dielectric constant) of the suspension. This influence depends on the concentration, viability, size, and even the cell shape. Hence, by measuring the permittivity, various fermentation processes can be monitored (e.g., in wine making and preparation of milk products). Thereby, the complex impedance (or admittance) between electrodes immersed into the suspension is measured and the permittivity is obtained by a suitable de-embedding procedure.
There exist various data in the literature on this influence, but they do not provide sufficient information for wide implementation of the technique. The aim of the paper was to experimentally investigate various aspects of the measurement procedures and establish practical guidelines and limitations.
Measurements were performed using an LCR meter, a classical vector network analyzer, and a nanoVNA analyzer, in the frequency range from 10 Hz to 100 MHz. Various suspension containers and systems of electrodes were designed and manufactured.
Bipolar systems of electrodes were found to be more suitable for higher frequencies than tetrapolar ones. Open electrode systems were found to be more prone to the influence of the environment than shielded systems (e.g., coaxial).
Good results were obtained for simple yeast suspensions. However, the presence of other cells and dispersed solids (e.g., in pressed grape juice) was found to completely overshadow the yeast cells. Electrochemical effects on the electrodes were found to be insignificant above around 200 kHz. Bubbles on electrodes, delamination, high concentrations of ions, and even temperature variations significantly hindered measurements in many cases.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Radio-frequency electrical characterization of viable-cell suspensions
SP  - 38
EP  - 38
UR  - https://hdl.handle.net/21.15107/rcub_dais_16182
ER  - 

@conference{
author = "Dinkić, J. and Lević, S. M. and Nedović, Viktor and Obradović, Nina and Đorđević, Antonije",
year = "2023",
abstract = "Suspended viable cells significantly influence the relative complex permittivity (dielectric constant) of the suspension. This influence depends on the concentration, viability, size, and even the cell shape. Hence, by measuring the permittivity, various fermentation processes can be monitored (e.g., in wine making and preparation of milk products). Thereby, the complex impedance (or admittance) between electrodes immersed into the suspension is measured and the permittivity is obtained by a suitable de-embedding procedure.
There exist various data in the literature on this influence, but they do not provide sufficient information for wide implementation of the technique. The aim of the paper was to experimentally investigate various aspects of the measurement procedures and establish practical guidelines and limitations.
Measurements were performed using an LCR meter, a classical vector network analyzer, and a nanoVNA analyzer, in the frequency range from 10 Hz to 100 MHz. Various suspension containers and systems of electrodes were designed and manufactured.
Bipolar systems of electrodes were found to be more suitable for higher frequencies than tetrapolar ones. Open electrode systems were found to be more prone to the influence of the environment than shielded systems (e.g., coaxial).
Good results were obtained for simple yeast suspensions. However, the presence of other cells and dispersed solids (e.g., in pressed grape juice) was found to completely overshadow the yeast cells. Electrochemical effects on the electrodes were found to be insignificant above around 200 kHz. Bubbles on electrodes, delamination, high concentrations of ions, and even temperature variations significantly hindered measurements in many cases.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Radio-frequency electrical characterization of viable-cell suspensions",
pages = "38-38",
url = "https://hdl.handle.net/21.15107/rcub_dais_16182"
}

Dinkić, J., Lević, S. M., Nedović, V., Obradović, N.,& Đorđević, A.. (2023). Radio-frequency electrical characterization of viable-cell suspensions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 38-38.
https://hdl.handle.net/21.15107/rcub_dais_16182

Dinkić J, Lević SM, Nedović V, Obradović N, Đorđević A. Radio-frequency electrical characterization of viable-cell suspensions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:38-38.
https://hdl.handle.net/21.15107/rcub_dais_16182 .

Dinkić, J., Lević, S. M., Nedović, Viktor, Obradović, Nina, Đorđević, Antonije, "Radio-frequency electrical characterization of viable-cell suspensions" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):38-38,
https://hdl.handle.net/21.15107/rcub_dais_16182 .

TY  - CONF
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Bohannan, Eric W.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/16212
AB  - Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. The thermal treatment cycle included heating at 10 °C/min to 1600 °C followed by an isothermal hold for 2 hours under the vacuum (~20 Pa) in a resistance-heated graphite element furnace. This first step of the process promoted carbothermal reaction of the starting materials.
DSC-TGA was used to follow the carbothermal reaction. The onset temperature does not seem to change for non-activated and activated powders. The change in peak area may be related to the amount of the powder that reacts at this temperature. The catbothermal reaction was split into two parts for powders activated 60 and 120 minutes. Only part of the powder reacts at the initial
reaction, and then higher temperatures are required for full reaction.
PB  - Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)
C3  - Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)
T1  - Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA
SP  - 137
EP  - 137
UR  - https://hdl.handle.net/21.15107/rcub_dais_16212
ER  - 

@conference{
author = "Obradović, Nina and Filipović, Suzana and Bohannan, Eric W. and Fahrenholtz, William G.",
year = "2023",
abstract = "Mixtures of ZrO2 and C were prepared by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. As milling time increased, surface area of powders increased, indicating significant particle size reduction. The thermal treatment cycle included heating at 10 °C/min to 1600 °C followed by an isothermal hold for 2 hours under the vacuum (~20 Pa) in a resistance-heated graphite element furnace. This first step of the process promoted carbothermal reaction of the starting materials.
DSC-TGA was used to follow the carbothermal reaction. The onset temperature does not seem to change for non-activated and activated powders. The change in peak area may be related to the amount of the powder that reacts at this temperature. The catbothermal reaction was split into two parts for powders activated 60 and 120 minutes. Only part of the powder reacts at the initial
reaction, and then higher temperatures are required for full reaction.",
publisher = "Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)",
journal = "Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)",
title = "Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA",
pages = "137-137",
url = "https://hdl.handle.net/21.15107/rcub_dais_16212"
}

Obradović, N., Filipović, S., Bohannan, E. W.,& Fahrenholtz, W. G.. (2023). Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA. in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7)
Brno : Central and Eastern European Committee for Thermal Analysis and Calorimetry (CEEC-TAC)., 137-137.
https://hdl.handle.net/21.15107/rcub_dais_16212

Obradović N, Filipović S, Bohannan EW, Fahrenholtz WG. Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA. in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7). 2023;:137-137.
https://hdl.handle.net/21.15107/rcub_dais_16212 .

Obradović, Nina, Filipović, Suzana, Bohannan, Eric W., Fahrenholtz, William G., "Carbothermal reaction of mechanically activated ZrC powders followed by DSC-TGA" in Book of abstracts of the 7th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC7) (2023):137-137,
https://hdl.handle.net/21.15107/rcub_dais_16212 .

TY  - CONF
AU  - Peleš Tadić, Adriana
AU  - Živojinović, Jelena
AU  - Tadić, Nenad
AU  - Lević, Steva
AU  - Marković, Smilja
AU  - Pavlović, Vladimir B.
AU  - Filipović, Suzana
AU  - Obradović, Nina
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15759
AB  - Magnesium aluminate spinel (MgAl2O4) is a material with good mechanical, chemical, and thermal properties, low dielectric permeability and loss tangent. Based on those properties, MgAl2O4 has found a significant application in refractory ceramics, ceramics windows, integrated electronic devices, etc. Also, it possesses a high chemical and radiation resistance. In this research, MgO was calcined at 1000ºC for an hour, with a step of 10ºC/min to avoid presence of hydroxide or carbonate. MgO and Al2O3 powders were mixed in a one-to-one molar ratio afterwards. The powders were mechanically activated for 15, 30, and 60 minutes. The mass ratio of powder and balls was 1:40. The mechanically activated powders are pressed in the tablets, under the pressure of 0.5 t. The pressed powders were heated up to 1300 ºC with a step of 10 ºC/min and held for 1 h for the reaction. Reacted pellets were crushed and sieved. Obtained spinel powders were sintered at 1450 ºC for 2 h. Both sintered and non-sintered samples were investigated by XRD and SEM. The particle size distribution of the reacted powders was investigated by laser diffraction analysis. Raman spectroscopy was used to determine the lattice vibration in the sintered samples. All results are in accordance with our previous results, and the pure dense spinel phase is obtained.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
T1  - Structural characteristics of MgAl2O4 spinel
SP  - 52
EP  - 52
UR  - https://hdl.handle.net/21.15107/rcub_dais_15759
ER  - 

@conference{
author = "Peleš Tadić, Adriana and Živojinović, Jelena and Tadić, Nenad and Lević, Steva and Marković, Smilja and Pavlović, Vladimir B. and Filipović, Suzana and Obradović, Nina",
year = "2023",
abstract = "Magnesium aluminate spinel (MgAl2O4) is a material with good mechanical, chemical, and thermal properties, low dielectric permeability and loss tangent. Based on those properties, MgAl2O4 has found a significant application in refractory ceramics, ceramics windows, integrated electronic devices, etc. Also, it possesses a high chemical and radiation resistance. In this research, MgO was calcined at 1000ºC for an hour, with a step of 10ºC/min to avoid presence of hydroxide or carbonate. MgO and Al2O3 powders were mixed in a one-to-one molar ratio afterwards. The powders were mechanically activated for 15, 30, and 60 minutes. The mass ratio of powder and balls was 1:40. The mechanically activated powders are pressed in the tablets, under the pressure of 0.5 t. The pressed powders were heated up to 1300 ºC with a step of 10 ºC/min and held for 1 h for the reaction. Reacted pellets were crushed and sieved. Obtained spinel powders were sintered at 1450 ºC for 2 h. Both sintered and non-sintered samples were investigated by XRD and SEM. The particle size distribution of the reacted powders was investigated by laser diffraction analysis. Raman spectroscopy was used to determine the lattice vibration in the sintered samples. All results are in accordance with our previous results, and the pure dense spinel phase is obtained.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023",
title = "Structural characteristics of MgAl2O4 spinel",
pages = "52-52",
url = "https://hdl.handle.net/21.15107/rcub_dais_15759"
}

Peleš Tadić, A., Živojinović, J., Tadić, N., Lević, S., Marković, S., Pavlović, V. B., Filipović, S.,& Obradović, N.. (2023). Structural characteristics of MgAl2O4 spinel. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
Belgrade : Serbian Ceramic Society., 52-52.
https://hdl.handle.net/21.15107/rcub_dais_15759

Peleš Tadić A, Živojinović J, Tadić N, Lević S, Marković S, Pavlović VB, Filipović S, Obradović N. Structural characteristics of MgAl2O4 spinel. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023. 2023;:52-52.
https://hdl.handle.net/21.15107/rcub_dais_15759 .

Peleš Tadić, Adriana, Živojinović, Jelena, Tadić, Nenad, Lević, Steva, Marković, Smilja, Pavlović, Vladimir B., Filipović, Suzana, Obradović, Nina, "Structural characteristics of MgAl2O4 spinel" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023 (2023):52-52,
https://hdl.handle.net/21.15107/rcub_dais_15759 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Fahrenholtz, William G.
AU  - Marinković, Bojan A.
AU  - Rogan, Jelena
AU  - Lević, Steva
AU  - Đorđević, Antonije
AU  - Pavlović, Vladimir B.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14704
AB  - Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800°C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All powders were examined for phase composition, crystal structure, and morphology. The obtained results showed that by increasing the temperature, samples with higher density were synthesized. Milling for 1 h led to formation of larger particles, but finer powders after milling. XRPD and Raman spectroscopy showed disorder in the crystal structure after milling.
AB  - Магнезијум алуминат поседује структуру спинела и добра механичка, хемијска и термичка својства. Има широк спектар примене, укључујући рефракторну керамику, оружје и оптички транспарентна керамичка стакла. Ниска диелектрична пермеабилност и тангенс губитака пружају овој керамици примену и у електричним направама. У овом раду, прахови MgO и Al2O3 су помешани у моларном односу 1:1 и калцинисани на температурама између 1500°C и 1800°C да би се добио спинел. Након тога, узорци су смрвљени и механички активирани у млину током 60 минута да би се добио фини уситњен прах. Одређени су фазни састав, кристална структура и морфологија свих прахова. Резултати су показали да са порастом температуре расте и густина синтетисаних узорака. Млевење од 1 сата води ка формирању већих честица, али финијих прахова након млевења. XRPD и Раман спектроскопија указују на неуређену кристалну структуру након млевења.
PB  - ETRAN
T2  - Science of Sintering
T1  - Morphological and Structural Characterization of MgAl2O4 Spinel
SP  - 1
EP  - 10
VL  - 55
IS  - 1
DO  - 10.2298/SOS2301001O
UR  - https://hdl.handle.net/21.15107/rcub_dais_14704
ER  - 

@article{
author = "Obradović, Nina and Filipović, Suzana and Fahrenholtz, William G. and Marinković, Bojan A. and Rogan, Jelena and Lević, Steva and Đorđević, Antonije and Pavlović, Vladimir B.",
year = "2023",
abstract = "Magnesium aluminate has the spinel structure along with good mechanical, chemical, and thermal properties. Magnesium aluminate has a wide range of applications including refractory ceramics, optically transparent ceramic windows, and armors. Its low dielectric permeability and low loss tangent enable its applications for integrated electronic devices, as well. In this paper, MgO and Al2O3 powders were mixed in a one-to-one molar ratio and calcined at temperatures ranging from 1500 to 1800°C to produce phase pure spinel. Thereafter, pellets were crushed and treated in a planetary ball mill for 60 min to obtain a fine powder. All powders were examined for phase composition, crystal structure, and morphology. The obtained results showed that by increasing the temperature, samples with higher density were synthesized. Milling for 1 h led to formation of larger particles, but finer powders after milling. XRPD and Raman spectroscopy showed disorder in the crystal structure after milling., Магнезијум алуминат поседује структуру спинела и добра механичка, хемијска и термичка својства. Има широк спектар примене, укључујући рефракторну керамику, оружје и оптички транспарентна керамичка стакла. Ниска диелектрична пермеабилност и тангенс губитака пружају овој керамици примену и у електричним направама. У овом раду, прахови MgO и Al2O3 су помешани у моларном односу 1:1 и калцинисани на температурама између 1500°C и 1800°C да би се добио спинел. Након тога, узорци су смрвљени и механички активирани у млину током 60 минута да би се добио фини уситњен прах. Одређени су фазни састав, кристална структура и морфологија свих прахова. Резултати су показали да са порастом температуре расте и густина синтетисаних узорака. Млевење од 1 сата води ка формирању већих честица, али финијих прахова након млевења. XRPD и Раман спектроскопија указују на неуређену кристалну структуру након млевења.",
publisher = "ETRAN",
journal = "Science of Sintering",
title = "Morphological and Structural Characterization of MgAl2O4 Spinel",
pages = "1-10",
volume = "55",
number = "1",
doi = "10.2298/SOS2301001O",
url = "https://hdl.handle.net/21.15107/rcub_dais_14704"
}

Obradović, N., Filipović, S., Fahrenholtz, W. G., Marinković, B. A., Rogan, J., Lević, S., Đorđević, A.,& Pavlović, V. B.. (2023). Morphological and Structural Characterization of MgAl2O4 Spinel. in Science of Sintering
ETRAN., 55(1), 1-10.
https://doi.org/10.2298/SOS2301001O
https://hdl.handle.net/21.15107/rcub_dais_14704

Obradović N, Filipović S, Fahrenholtz WG, Marinković BA, Rogan J, Lević S, Đorđević A, Pavlović VB. Morphological and Structural Characterization of MgAl2O4 Spinel. in Science of Sintering. 2023;55(1):1-10.
doi:10.2298/SOS2301001O
https://hdl.handle.net/21.15107/rcub_dais_14704 .

Obradović, Nina, Filipović, Suzana, Fahrenholtz, William G., Marinković, Bojan A., Rogan, Jelena, Lević, Steva, Đorđević, Antonije, Pavlović, Vladimir B., "Morphological and Structural Characterization of MgAl2O4 Spinel" in Science of Sintering, 55, no. 1 (2023):1-10,
https://doi.org/10.2298/SOS2301001O .,
https://hdl.handle.net/21.15107/rcub_dais_14704 .

TY  - JOUR
AU  - Silvestroni, Laura
AU  - Gilli, Nicola
AU  - Sangiorgi, Alex
AU  - Corozzi, Alessandro
AU  - Filipović, Suzana
AU  - Obradović, Nina
AU  - Ortiz-Membrado, Laia
AU  - Jiménez-Piqué, Emilio
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14009
AB  - Multi-phase ceramics based on ZrB2, TiB2 and doped with CrB2 and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex (Zr,Ti,Cr)B2 solid solutions. Core–shell structures formed in TiB2 grains, whereas ZrB2 appeared to form a homogeneous solid solution with the other metals. Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere. In addition, atomic size factors explicated the precipitation of CrB2 nano-particles into ZrB2-rich grains and of ZrB2 nano-particles into TiB2-rich grains. The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.
PB  - Tsinghua University Press
T2  - Journal of Advanced Ceramics
T1  - Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties
SP  - 414
EP  - 431
VL  - 12
IS  - 2
DO  - 10.26599/JAC.2023.9220695
UR  - https://hdl.handle.net/21.15107/rcub_dais_14009
ER  - 

@article{
author = "Silvestroni, Laura and Gilli, Nicola and Sangiorgi, Alex and Corozzi, Alessandro and Filipović, Suzana and Obradović, Nina and Ortiz-Membrado, Laia and Jiménez-Piqué, Emilio and Fahrenholtz, William G.",
year = "2023",
abstract = "Multi-phase ceramics based on ZrB2, TiB2 and doped with CrB2 and SiC were prepared by powder metallurgy and hot pressing to explore the possibility of obtaining multi-scale microstructures by super-saturation of complex (Zr,Ti,Cr)B2 solid solutions. Core–shell structures formed in TiB2 grains, whereas ZrB2 appeared to form a homogeneous solid solution with the other metals. Precipitation of nano-inclusions within both micron-sized borides was assessed by transmission electron microscopy and thermodynamics elucidated the preferential formation of boride inclusions due to the specific sintering atmosphere. In addition, atomic size factors explicated the precipitation of CrB2 nano-particles into ZrB2-rich grains and of ZrB2 nano-particles into TiB2-rich grains. The hardness of the constituent phases measured by nanoindentation ranged from 36 to 43 GPa.",
publisher = "Tsinghua University Press",
journal = "Journal of Advanced Ceramics",
title = "Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties",
pages = "414-431",
volume = "12",
number = "2",
doi = "10.26599/JAC.2023.9220695",
url = "https://hdl.handle.net/21.15107/rcub_dais_14009"
}

Silvestroni, L., Gilli, N., Sangiorgi, A., Corozzi, A., Filipović, S., Obradović, N., Ortiz-Membrado, L., Jiménez-Piqué, E.,& Fahrenholtz, W. G.. (2023). Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties. in Journal of Advanced Ceramics
Tsinghua University Press., 12(2), 414-431.
https://doi.org/10.26599/JAC.2023.9220695
https://hdl.handle.net/21.15107/rcub_dais_14009

Silvestroni L, Gilli N, Sangiorgi A, Corozzi A, Filipović S, Obradović N, Ortiz-Membrado L, Jiménez-Piqué E, Fahrenholtz WG. Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties. in Journal of Advanced Ceramics. 2023;12(2):414-431.
doi:10.26599/JAC.2023.9220695
https://hdl.handle.net/21.15107/rcub_dais_14009 .

Silvestroni, Laura, Gilli, Nicola, Sangiorgi, Alex, Corozzi, Alessandro, Filipović, Suzana, Obradović, Nina, Ortiz-Membrado, Laia, Jiménez-Piqué, Emilio, Fahrenholtz, William G., "Multi-phase (Zr,Ti,Cr)B2solid solutions: Preparation, multi-scale microstructure, and local properties" in Journal of Advanced Ceramics, 12, no. 2 (2023):414-431,
https://doi.org/10.26599/JAC.2023.9220695 .,
https://hdl.handle.net/21.15107/rcub_dais_14009 .

TY  - JOUR
AU  - Kosanović, Darko
AU  - Blagojević, Vladimir
AU  - Aleksić, Stanko
AU  - Živojinović, Jelena
AU  - Peleš Tadić, Adriana
AU  - Pavlović, Vladimir B.
AU  - Obradović, Nina
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14971
AB  - BZT ceramics was prepared by using fine powder mixture of BaCO3, TiO2 and ZrO2 in the respective molar ratio to form Ba(Zr0.10Ti0.90)O3 via solid state reaction at elevated temperature. The prepared BZT was milled in the planetary ball mill from 0-120 min to achieve different powder grades from micron to nano-sized particles. After the powder characterization by XRD and SEM the samples were pressed in disc shape and sintered at different temperatures from 1100-1350°C in the air. The sintered samples were characterized by SEM and their density and average grain size was determined and presented vs. sintering temperature and powder grades (milling time). After that the silver epoxy electrodes were deposited on sintered disc samples. The disc samples capacity and resistivity were measured at low frequency region from 1 Hz to 200 kHz using low frequency impedance analyzer. The sintering temperatures and powder grades were used as parameters. Finally the specific resistance ρ, dielectric constant (ε' + jε") and tgδ where determined from the impedance measurements. The behavior of electronic properties where analyzed e.g. the relaxation effect of the space charge (inter-granular electric charges) vs. sintering temperature and ceramic grades. The results obtained were compared with best literature data for the losses in BZT ceramics at low frequencies.
PB  - Belgrade : ETRAN
T2  - Science of Sintering
T1  - Electronic properties of BZT nano-ceramic grades at low frequency region
SP  - 413
EP  - 423
VL  - 55
IS  - 3
DO  - 10.2298/SOS230717043K
UR  - https://hdl.handle.net/21.15107/rcub_dais_14971
ER  - 

@article{
author = "Kosanović, Darko and Blagojević, Vladimir and Aleksić, Stanko and Živojinović, Jelena and Peleš Tadić, Adriana and Pavlović, Vladimir B. and Obradović, Nina",
year = "2023",
abstract = "BZT ceramics was prepared by using fine powder mixture of BaCO3, TiO2 and ZrO2 in the respective molar ratio to form Ba(Zr0.10Ti0.90)O3 via solid state reaction at elevated temperature. The prepared BZT was milled in the planetary ball mill from 0-120 min to achieve different powder grades from micron to nano-sized particles. After the powder characterization by XRD and SEM the samples were pressed in disc shape and sintered at different temperatures from 1100-1350°C in the air. The sintered samples were characterized by SEM and their density and average grain size was determined and presented vs. sintering temperature and powder grades (milling time). After that the silver epoxy electrodes were deposited on sintered disc samples. The disc samples capacity and resistivity were measured at low frequency region from 1 Hz to 200 kHz using low frequency impedance analyzer. The sintering temperatures and powder grades were used as parameters. Finally the specific resistance ρ, dielectric constant (ε' + jε") and tgδ where determined from the impedance measurements. The behavior of electronic properties where analyzed e.g. the relaxation effect of the space charge (inter-granular electric charges) vs. sintering temperature and ceramic grades. The results obtained were compared with best literature data for the losses in BZT ceramics at low frequencies.",
publisher = "Belgrade : ETRAN",
journal = "Science of Sintering",
title = "Electronic properties of BZT nano-ceramic grades at low frequency region",
pages = "413-423",
volume = "55",
number = "3",
doi = "10.2298/SOS230717043K",
url = "https://hdl.handle.net/21.15107/rcub_dais_14971"
}

Kosanović, D., Blagojević, V., Aleksić, S., Živojinović, J., Peleš Tadić, A., Pavlović, V. B.,& Obradović, N.. (2023). Electronic properties of BZT nano-ceramic grades at low frequency region. in Science of Sintering
Belgrade : ETRAN., 55(3), 413-423.
https://doi.org/10.2298/SOS230717043K
https://hdl.handle.net/21.15107/rcub_dais_14971

Kosanović D, Blagojević V, Aleksić S, Živojinović J, Peleš Tadić A, Pavlović VB, Obradović N. Electronic properties of BZT nano-ceramic grades at low frequency region. in Science of Sintering. 2023;55(3):413-423.
doi:10.2298/SOS230717043K
https://hdl.handle.net/21.15107/rcub_dais_14971 .

Kosanović, Darko, Blagojević, Vladimir, Aleksić, Stanko, Živojinović, Jelena, Peleš Tadić, Adriana, Pavlović, Vladimir B., Obradović, Nina, "Electronic properties of BZT nano-ceramic grades at low frequency region" in Science of Sintering, 55, no. 3 (2023):413-423,
https://doi.org/10.2298/SOS230717043K .,
https://hdl.handle.net/21.15107/rcub_dais_14971 .

TY  - JOUR
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, Miljana
AU  - Kosanović, Darko
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/14890
AB  - Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.
PB  - Elsevier BV
T2  - Journal of the European Ceramic Society
T1  - Effect of mechanical activation on carbothermal synthesis and densification of ZrC
SP  - 7306
EP  - 7313
DO  - 10.1016/j.jeurceramsoc.2023.08.007
UR  - https://hdl.handle.net/21.15107/rcub_dais_14890
ER  - 

@article{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, Miljana and Kosanović, Darko and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Zirconium carbide ceramics were prepared by carbothermal reduction of ZrO2 and C that were mixed by high-energy ball milling. Powders were milled for times from 0 to 120 min in air. As milling time increased, the surface area of the powders increased, indicating significant particle size reduction. Milled powders were reacted at 1600 °C and then densified by spark plasma sintering at 2000 °C, which was sufficient to convert the starting powders to zirconium carbide. Unmilled powders did not reach full density. Milled powders reached full density, but ZrO2 impurities were found for specimens prepared from powders milled for 60 and 120 min. Microstructure analysis showed that grain size was less than 2 µm for ceramics produced from powder milled for 15 min. Based on densification onset temperature and impurity levels, a milling time of 15 min gives the best balance of particle size reduction to promote densification while minimizing impurity levels.",
publisher = "Elsevier BV",
journal = "Journal of the European Ceramic Society",
title = "Effect of mechanical activation on carbothermal synthesis and densification of ZrC",
pages = "7306-7313",
doi = "10.1016/j.jeurceramsoc.2023.08.007",
url = "https://hdl.handle.net/21.15107/rcub_dais_14890"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Rogan, J.,& Fahrenholtz, W. G.. (2023). Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society
Elsevier BV., 7306-7313.
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14890

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Rogan J, Fahrenholtz WG. Effect of mechanical activation on carbothermal synthesis and densification of ZrC. in Journal of the European Ceramic Society. 2023;:7306-7313.
doi:10.1016/j.jeurceramsoc.2023.08.007
https://hdl.handle.net/21.15107/rcub_dais_14890 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, Miljana, Kosanović, Darko, Rogan, Jelena, Fahrenholtz, William G., "Effect of mechanical activation on carbothermal synthesis and densification of ZrC" in Journal of the European Ceramic Society (2023):7306-7313,
https://doi.org/10.1016/j.jeurceramsoc.2023.08.007 .,
https://hdl.handle.net/21.15107/rcub_dais_14890 .

TY  - CONF
AU  - Filipović, Suzana
AU  - Smith, Steven
AU  - Obradović, Nina
AU  - Hilmas, Gregory E.
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15224
AB  - High entropy carbide/boride (HEC/HEB) ceramics are materials with a wide range of possible applications in harsh environments due to their good mechanical properties, oxidation resistance, and thermal stability. They are usually formed by the solid solutioning of four or more transition metals (TM) in the boride and carbide lattice. In this research, boro/carbothermal reduction was used to form an individual diboride and carbide phases from oxide mixtures. The stoichiometry of the reaction was varied in order to synthesize pure dual phase ceramics. The reacted powders were spark plasma sintered (SPS) or hot pressed (HP), using a two-step process, to produce dense ceramics and to develop the solid solutions. Ceramics processed by SPS still contained residual oxides, while ceramics produced by HP were nominally phase-pure high entropy dual phase materials. Preferential segregation of the TMs was detected by energy dispersive spectroscopy. Vickers hardness measurements confirmed that the highest hardness was obtained for specimens densified by HP at 1950°C that contained no residual oxides and had the smallest grain size. The hardness increased from 25.7 ± 0.2 GPa to 33.6 ± 2.2 GPa with decrease applied load from 9.81N to 0.49N, respectively.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.
T1  - Optimization of processing parameters for high entropy dual phase ceramics
SP  - 53
EP  - 53
UR  - https://hdl.handle.net/21.15107/rcub_dais_15224
ER  - 

@conference{
author = "Filipović, Suzana and Smith, Steven and Obradović, Nina and Hilmas, Gregory E. and Fahrenholtz, William G.",
year = "2023",
abstract = "High entropy carbide/boride (HEC/HEB) ceramics are materials with a wide range of possible applications in harsh environments due to their good mechanical properties, oxidation resistance, and thermal stability. They are usually formed by the solid solutioning of four or more transition metals (TM) in the boride and carbide lattice. In this research, boro/carbothermal reduction was used to form an individual diboride and carbide phases from oxide mixtures. The stoichiometry of the reaction was varied in order to synthesize pure dual phase ceramics. The reacted powders were spark plasma sintered (SPS) or hot pressed (HP), using a two-step process, to produce dense ceramics and to develop the solid solutions. Ceramics processed by SPS still contained residual oxides, while ceramics produced by HP were nominally phase-pure high entropy dual phase materials. Preferential segregation of the TMs was detected by energy dispersive spectroscopy. Vickers hardness measurements confirmed that the highest hardness was obtained for specimens densified by HP at 1950°C that contained no residual oxides and had the smallest grain size. The hardness increased from 25.7 ± 0.2 GPa to 33.6 ± 2.2 GPa with decrease applied load from 9.81N to 0.49N, respectively.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.",
title = "Optimization of processing parameters for high entropy dual phase ceramics",
pages = "53-53",
url = "https://hdl.handle.net/21.15107/rcub_dais_15224"
}

Filipović, S., Smith, S., Obradović, N., Hilmas, G. E.,& Fahrenholtz, W. G.. (2023). Optimization of processing parameters for high entropy dual phase ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.
Belgrade : Serbian Ceramic Society., 53-53.
https://hdl.handle.net/21.15107/rcub_dais_15224

Filipović S, Smith S, Obradović N, Hilmas GE, Fahrenholtz WG. Optimization of processing parameters for high entropy dual phase ceramics. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023.. 2023;:53-53.
https://hdl.handle.net/21.15107/rcub_dais_15224 .

Filipović, Suzana, Smith, Steven, Obradović, Nina, Hilmas, Gregory E., Fahrenholtz, William G., "Optimization of processing parameters for high entropy dual phase ceramics" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023. (2023):53-53,
https://hdl.handle.net/21.15107/rcub_dais_15224 .

TY  - CONF
AU  - Aleksić, Stanko
AU  - Obradović, Nina
AU  - Mitrović, Nebojša S.
AU  - Luković, Miloljub D.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15156
AB  - A powder of Cu0.2Ni0.5Zn1.0 Mn1.3O4 composition for custom thermistor was prepared by using a certain mixture of metal oxides and solid state reaction at 1000 °C/4h in air. The obtained thermistor powder was milled in the planetary ball mill and agate mill for a prolonged time to achieve submicron powder. The prepared thermistor powder was further characterized by using XRD and SEM techniques. After that, the thermistor powder was pressed into small disc-shaped samples and sintered at 1150 °C/2h. The sintered samples were also characterized by using XRD and SEM. The main electrical properties such as nominal resistance R and thermistor exponential factor B were measured in the climatic test chamber. After that, the thick film paste was prepared using the same powder, an organic vehicle and a glass frit. The paste was printed on alumina substrate, dried at 150 °C / 30 min and sintered in air at 850 °C / 10 min in the hybrid conveyor furnace. The planar electrodes were printed on the sintered NTC thermistor layer using the PdAg thick film paste. The electric properties of sintered thick film thermistor were also measured in the climatic test chamber. The obtained results were used for development of novel self-heating thermistor applications.
PB  - Belgrade : Serbian Ceramic Society
C3  - Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
T1  - Characterization of NTC thick film thermistor paste Cu0.2 Ni0.5 Zn1.0 Mn1.3O4
SP  - 70
EP  - 71
UR  - https://hdl.handle.net/21.15107/rcub_dais_15156
ER  - 

@conference{
author = "Aleksić, Stanko and Obradović, Nina and Mitrović, Nebojša S. and Luković, Miloljub D.",
year = "2023",
abstract = "A powder of Cu0.2Ni0.5Zn1.0 Mn1.3O4 composition for custom thermistor was prepared by using a certain mixture of metal oxides and solid state reaction at 1000 °C/4h in air. The obtained thermistor powder was milled in the planetary ball mill and agate mill for a prolonged time to achieve submicron powder. The prepared thermistor powder was further characterized by using XRD and SEM techniques. After that, the thermistor powder was pressed into small disc-shaped samples and sintered at 1150 °C/2h. The sintered samples were also characterized by using XRD and SEM. The main electrical properties such as nominal resistance R and thermistor exponential factor B were measured in the climatic test chamber. After that, the thick film paste was prepared using the same powder, an organic vehicle and a glass frit. The paste was printed on alumina substrate, dried at 150 °C / 30 min and sintered in air at 850 °C / 10 min in the hybrid conveyor furnace. The planar electrodes were printed on the sintered NTC thermistor layer using the PdAg thick film paste. The electric properties of sintered thick film thermistor were also measured in the climatic test chamber. The obtained results were used for development of novel self-heating thermistor applications.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023",
title = "Characterization of NTC thick film thermistor paste Cu0.2 Ni0.5 Zn1.0 Mn1.3O4",
pages = "70-71",
url = "https://hdl.handle.net/21.15107/rcub_dais_15156"
}

Aleksić, S., Obradović, N., Mitrović, N. S.,& Luković, M. D.. (2023). Characterization of NTC thick film thermistor paste Cu0.2 Ni0.5 Zn1.0 Mn1.3O4. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023
Belgrade : Serbian Ceramic Society., 70-71.
https://hdl.handle.net/21.15107/rcub_dais_15156

Aleksić S, Obradović N, Mitrović NS, Luković MD. Characterization of NTC thick film thermistor paste Cu0.2 Ni0.5 Zn1.0 Mn1.3O4. in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023. 2023;:70-71.
https://hdl.handle.net/21.15107/rcub_dais_15156 .

Aleksić, Stanko, Obradović, Nina, Mitrović, Nebojša S., Luković, Miloljub D., "Characterization of NTC thick film thermistor paste Cu0.2 Ni0.5 Zn1.0 Mn1.3O4" in Program and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian Academy of Sciences and Art Serbia, Belgrade,18-20.September 2023 (2023):70-71,
https://hdl.handle.net/21.15107/rcub_dais_15156 .

TY  - CONF
AU  - Kosanović, Darko
AU  - Fahrenholtz, William G.
AU  - Obradović, Nina
AU  - Filipović, Suzana
AU  - Watts, Jeremy L.
AU  - Hilmas, G. E.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15009
AB  - The thermal properties of zirconium diboride (ZrB2) ceramics with tungsten additions of up to 5 wt% were characterized up to 2000°C. Densification was promoted by the addition of 0.5 wt% carbon. ZrB2 ceramics were prepared from commercially available powder by hot pressing. The crystalline phases present were determined by x-ray diffraction. The microstructure and density change as a result of the addition of tungsten, but this does not affect much the thermal behavior of ZrB2 at room and elevated temperatures. Thermal diffusivity at 200°C decreased from 0.158 cm2/s for nominally pure ZrB2 to 0.149 cm2/s for ZrB2 with 5 wt% Tungsten carbide (WC). The thermal diffusivity decreased with increasing temperature, reaching a value of 0.145 cm2/s at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Heat capacity, unlike thermal diffusivity, did not change during thermal cycling. Thermal conductivity, which was calculated from thermal diffusivity, heat capacity, and density, was as high as 77.9 W/(m·K) at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Any level of Tungsten carbide (WC) contamination reduces thermal conductivity. Properties, including hardness, oxygen content, elastic modulus, strength were measured and will be discussed.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions
SP  - 79
UR  - https://hdl.handle.net/21.15107/rcub_dais_15009
ER  - 

@conference{
author = "Kosanović, Darko and Fahrenholtz, William G. and Obradović, Nina and Filipović, Suzana and Watts, Jeremy L. and Hilmas, G. E.",
year = "2023",
abstract = "The thermal properties of zirconium diboride (ZrB2) ceramics with tungsten additions of up to 5 wt% were characterized up to 2000°C. Densification was promoted by the addition of 0.5 wt% carbon. ZrB2 ceramics were prepared from commercially available powder by hot pressing. The crystalline phases present were determined by x-ray diffraction. The microstructure and density change as a result of the addition of tungsten, but this does not affect much the thermal behavior of ZrB2 at room and elevated temperatures. Thermal diffusivity at 200°C decreased from 0.158 cm2/s for nominally pure ZrB2 to 0.149 cm2/s for ZrB2 with 5 wt% Tungsten carbide (WC). The thermal diffusivity decreased with increasing temperature, reaching a value of 0.145 cm2/s at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Heat capacity, unlike thermal diffusivity, did not change during thermal cycling. Thermal conductivity, which was calculated from thermal diffusivity, heat capacity, and density, was as high as 77.9 W/(m·K) at 2000°C for ZrB2 with 5 wt% Tungsten carbide (WC). Any level of Tungsten carbide (WC) contamination reduces thermal conductivity. Properties, including hardness, oxygen content, elastic modulus, strength were measured and will be discussed.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions",
pages = "79",
url = "https://hdl.handle.net/21.15107/rcub_dais_15009"
}

Kosanović, D., Fahrenholtz, W. G., Obradović, N., Filipović, S., Watts, J. L.,& Hilmas, G. E.. (2023). Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 79.
https://hdl.handle.net/21.15107/rcub_dais_15009

Kosanović D, Fahrenholtz WG, Obradović N, Filipović S, Watts JL, Hilmas GE. Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:79.
https://hdl.handle.net/21.15107/rcub_dais_15009 .

Kosanović, Darko, Fahrenholtz, William G., Obradović, Nina, Filipović, Suzana, Watts, Jeremy L., Hilmas, G. E., "Elevated Temperature Thermal Properties of ZrB2 with Tungsten Additions" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):79,
https://hdl.handle.net/21.15107/rcub_dais_15009 .

TY  - CONF
AU  - Obradović, Nina
AU  - Feng, Lun
AU  - Filipović, Suzana
AU  - Mirković, M.
AU  - Kosanović, Darko
AU  - Živojinović, Jelena
AU  - Rogan, Jelena
AU  - Fahrenholtz, William G.
PY  - 2023
UR  - https://dais.sanu.ac.rs/123456789/15008
AB  - Mechanical activation represents a very useful technique for powder processing prior to sintering process. First of all, it makes powders homogenized, leads to attrition of powder particles, and makes powder mixtures more reactive. Secondly, it can lead to mechano-chemical reaction, and finally, lowering of sintering time and temperature. Mixtures of ZrO2 and C were mechanically activated by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. Mechanically activated powder mixtures were characterized by various techniques, such as particle size analysis (PSA), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and diffraction scanning calorimetry along with thermo gravimetry (DSC-TGA). As milling time increased, surface area of powders increased, indicating significant particle size reduction. Mechanical activation for 15 minutes provides the best balance between particle size reduction and reactivity for the powders.
PB  - Belgrade : University of Belgrade - Faculty of Mechanical Engineering
C3  - Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
T1  - Characterization of mechanically activated ZrO2-C powder mixtures
SP  - 78
UR  - https://hdl.handle.net/21.15107/rcub_dais_15008
ER  - 

@conference{
author = "Obradović, Nina and Feng, Lun and Filipović, Suzana and Mirković, M. and Kosanović, Darko and Živojinović, Jelena and Rogan, Jelena and Fahrenholtz, William G.",
year = "2023",
abstract = "Mechanical activation represents a very useful technique for powder processing prior to sintering process. First of all, it makes powders homogenized, leads to attrition of powder particles, and makes powder mixtures more reactive. Secondly, it can lead to mechano-chemical reaction, and finally, lowering of sintering time and temperature. Mixtures of ZrO2 and C were mechanically activated by high-energy ball milling. Powders were milled for times from 0 to 120 minutes in air atmosphere. Mechanically activated powder mixtures were characterized by various techniques, such as particle size analysis (PSA), X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and diffraction scanning calorimetry along with thermo gravimetry (DSC-TGA). As milling time increased, surface area of powders increased, indicating significant particle size reduction. Mechanical activation for 15 minutes provides the best balance between particle size reduction and reactivity for the powders.",
publisher = "Belgrade : University of Belgrade - Faculty of Mechanical Engineering",
journal = "Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia",
title = "Characterization of mechanically activated ZrO2-C powder mixtures",
pages = "78",
url = "https://hdl.handle.net/21.15107/rcub_dais_15008"
}

Obradović, N., Feng, L., Filipović, S., Mirković, M., Kosanović, D., Živojinović, J., Rogan, J.,& Fahrenholtz, W. G.. (2023). Characterization of mechanically activated ZrO2-C powder mixtures. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia
Belgrade : University of Belgrade - Faculty of Mechanical Engineering., 78.
https://hdl.handle.net/21.15107/rcub_dais_15008

Obradović N, Feng L, Filipović S, Mirković M, Kosanović D, Živojinović J, Rogan J, Fahrenholtz WG. Characterization of mechanically activated ZrO2-C powder mixtures. in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia. 2023;:78.
https://hdl.handle.net/21.15107/rcub_dais_15008 .

Obradović, Nina, Feng, Lun, Filipović, Suzana, Mirković, M., Kosanović, Darko, Živojinović, Jelena, Rogan, Jelena, Fahrenholtz, William G., "Characterization of mechanically activated ZrO2-C powder mixtures" in Programme and The Book of Abstracts / International Conference of Experimental and Numerical Investigations and New Technologies - CNN TECH 2023, 04 – 07 July 2023, Zlatibor, Serbia (2023):78,
https://hdl.handle.net/21.15107/rcub_dais_15008 .