Dielectric and ferroelectric behaviour of Zr-doped BaTiO3 perovskites

Abstract

The crystal structure, microstructure, dielectric and ferroelectric behaviour of Ba(ZrxTi1-x)O3 (x = 0.05, 0.10, 0.15, 0.20, 0.25) perovskites fabricated by high-temperature solid state method were investigated. Zr4+ ions are dissolved completely into B-site of the matrix BaTiO3 within the studied composition range, leading to an expansion of the lattice. The average grain size decreased with Zr content increasing. In P-E loops, the remanent polarization gradually decreased with Zr-doping, indicating the depression of ferroelectricity. Temperature dependent dielectric properties at different frequencies exhibited obvious relaxor behaviour. It was shown that diffuseness coefficient γ increased from 1.45 (x = 0.05) to 1.89∼1.90 (x = 0.10-0.25) by using the modified Curie-Weiss law for the fit. The permittivity of the Ba(ZrxTi1-x)O3 ceramics at room temperature was largely improved by Zr-doping, thus when x = 0.20, εr (1 kHz) = 10790.