Characterization and microstructure evolution in Er-DOPED BaTiO3 ceramics

Abstract

BaTiO3-ceramics are known as some of the most useful electroceramics with a various applications. In this study the effect of Er 2O3 as additive on the microstructure and dielectric properties of doped BaTiO3 was investigated. The samples doped with 0.01 to 1.0 wt% Er2O3 were prepared using by conventional solid state procedure, and were sintered at 1350°C for four hours. The microstructure of sintered specimens was investigated by SEM-5300 and capacitance and dielectric loss measurements have been done using LCR-metra Agilent 4284A in the frequency range from 20Hz to 1MHz. The microstructure study with low additive concentration shows abnormal grain size, with average grain size between 20-60 μm. With the higher dopant concentracion the abnormal grain growth is inhibited and the grain size ranged between 5-15μm. The dielectric constant decrease with increase of dopant concentration and for all of the investigated samples ranged from 650 to 1600 at room temperature. The dissipation losses a linear decrease v.s frequency is mesured for all investigated samples. We applied a fractal method for the microstructure analysis. This method for analysis of the structure of ceramics provides a new approach for describing, predicting and modeling the grain shape and relations between the BaTiO3 ceramic structure and dielectrical properties.