Crystal structure and dielectric properties of layered perovskite-like solid solutions Bi3−x Gdx TiTaO9 (x = 0.0, 0.1, 0.2, 0.3) with high Curie temperature

Abstract

The Aurivillius phases [Bi2O2][A[Formula: see text][Formula: see text]O[Formula: see text]] are well-known ferroelectrics with high Curie temperatures [Formula: see text]. High-temperature piezoceramics Bi[Formula: see text][Formula: see text]TiTaO9 (BGdTTa, [Formula: see text]= 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 ([Formula: see text] = 2) with the orthorhombic crystal lattice (space group A21am). The temperature dependence of the relative permittivity [Formula: see text]/[Formula: see text] ([Formula: see text] of the compounds was measured and showed that the Curie temperature [Formula: see text] of perovskite-like oxides Bi[Formula: see text][Formula: see text]TiTaO9 increases linearly with an increase in the substitution parameter [Formula: see text] to [Formula: see text] = 925[Formula: see text]C. The activation energies of charge carriers have been found in different temperature ranges.