Lead-free Ba0.98Ca0.02Zr0.02Ti0.98O3 ceramics with enhanced electrical performance by modifying MnO2 doping content and sintering temperature

Abstract

Lead-free Ba0.98Ca0.02Zr0.02Ti0.98O3-xmol% MnO2 (BCZT-xMn) (x = 0.1, 0.2, 0.3, 0.4, 0.5) ceramics were prepared by conventional solid-state reaction method and the effects of MnO2 doping content and sintering temperature on microstructure and electrical properties of BCZT ceramics were studied. The ceramics samples with all MnO2 doping contents exhibit pure perovskite structure and similar Curie temperature of approximately 120 °C. Among all, the sample with 0.3 mol. % MnO2 doping content sintered at 1400 °C exhibits improved ferroelectricity with a relatively high remnant polarization (Pr) and low coercive electric field (Ec) of 15.7 μC/cm2 and 180 V/mm, respectively, which can be attributed to the fact that an appropriate doping content of MnO2 does favor to the grain growth, with the favorable effect on domain motion. Accordingly, excellent piezoelectric property with piezoelectric coefficient (d33) of 308 pC/N can be obtained. Besides, the sample shows a relatively low dielectric loss (tanδ) of 1.04%. As a result, the BCZT-xMn ceramic exhibits the potential to be used in memory and transformer applications.