Effects of scandium oxide on domain structure, dielectric and ferroelectric properties of barium zirconate titanate ceramics

Abstract

The Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ferroelectric ceramics were fabricated by the conventional solid state reaction method. The influences of Sc2O3 on their microstructure, especially domain structure, dielectric and ferroelectric properties were investigated by X-ray diffractometer, scanning electron microscope, LCR measurement system and ferroelectric tester. The Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ceramics are tetragonal perovskites with no impurity phases. The average grain size of Ba(Zr0.1Ti0.9)O3 ceramics decreases from ~40 µm to ~5 µm as the Sc2O3 content increases. Both the 90° ferroelectric domains and the 180° ones exist in the 0.2 mol% Sc2O3 doped Ba(Zr0.1Ti0.9)O3 ceramics with an average grain size of ~26 µm. The ferroelectric -paraelectric phase transition temperature and the dielectric permittivity maximum of Ba(Zr0.1Ti0.9)O3 ceramics decrease with increasing Sc2O3 doping content, while the temperature stability of relative dielectric constant is improved effectively after Sc2O3 modification in BZT ceramics. The remnant polarization and the coercive field of BZT ceramics decrease in Sc2O3 highly doped BZT ceramics as the Sc2O3 content increases.