Crystal structure and dielectric properties of layered perovskite-like solid solutions Bi 3-x Gd x TiTaO9(x = 0.0, 0.1, 0.2, 0.3) with high Curie temperature

Abstract

The Aurivillius phases [Bi2O2][An-1BnO3n+1] are well-known ferroelectrics with high Curie temperatures TC. High-temperature piezoceramics Bi3-xGdxTiTaO9 (BGdTTa, x= 0.0, 0.1, 0.2, 0.3) were prepared by a solid-state reaction method. The structural and electrophysical characteristics of BGdTTa ceramics have been studied. According to the data of powder X-ray diffraction, all the compounds are single-phase with the structures of two-layer Aurivillius phases (m = 2) with the orthorhombic crystal lattice (space group A21am). The temperature dependence of the relative permittivity/0 (T) of the compounds was measured and showed that the Curie temperature TC of perovskite-like oxides Bi3-xGdxTiTaO9 increases linearly with an increase in the substitution parameter x to TC = 925°C. The activation energies of charge carriers have been found in different temperature ranges.