INFLUENCE OF Yb2O3 AND Er2O3 ON BaTiO3 CERAMICS MICROSTRUCTURE AND CORRESPONDING ELECTRICAL PROPERTIES

In this article the additives Yb and Er oxides are used as doping materials for BaTiO3-based multilayer devices. The amphoteric behavior of these rare-earth ions leads to the increase of dielectric permittivity and decrease of dielectric losses. BaTiO3-ceramics doped with 0.01 up to 0.5 wt % of Yb2O3 and Er2O3 were prepared by conventional solid state procedure and sintered up to 1320 degrees C for four hours. In BaTiO3 doped with a low level of rare-earth ions the grain size ranged from 10-60 mu m. With the higher dopant concentration the abnormal grain growth is inhibited and the grain size ranged from between 2-10 mu m. The measurements of capacitance and dielectric losses as a function of frequency and temperature have been done in order to correlate the microstructure and dielectric properties of doped BaTiO3-ceramics. The temperature dependence of the dielectric constant as a function of dopant amount has been investigated.