Microstructure and dielectric properties of BaTiO3 doped with Er2O3, Yb2O3 and Ho 2O3

Abstract

Doped barium-titanate ceramic is attracting much interest for its application as resistors with a positive temperature coefficient of resistivity (PTCR), multilayer ceramic capacitors (MLCC), thermal sensors etc. In this article the influence of Yb2O3, Er2O 3 and Ho2O3 on microstructure development and dielectric properties of BaTiO3 ceramics has been presented. BaTiO3-ceramics doped with 0.5 up to 1 wt % of Yb2O 3, Er2O3 and Ho2O3 were prepared by conventional solid state procedure and sintered up to 1320°C for two hours. Microstructure investigations of doped BaTiO3 was performed using the scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and stereological methods. The measurements of capacitance and dielectric losses as a function of frequency and temperature were evaluated by matching model. Special attention has been focused on the study of the changes in morphology, grain and pore size distribution of the sintered specimens and their correlation with the change of capacity, dielectric permittivity and Curie temperature.