Effects of grain size on the electrical properties in the Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ ceramics

Abstract

Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramics are prepared by the conventional solid-state reaction route, and the effect of dwell time on the physical and electrical properties has been investigated. XRD patterns show that morphotropic phase boundaries exist in all BCZT ceramics. BCZT ceramics sintered at 1450 °C for 8 h exhibit the largest grain size (10.5 μm) and highest Curie temperature (Tc∼93 °C). BCZT ceramics exhibit the similar relaxor properties to ideal relaxor ferroeletric. Meanwhile, the behavior of diffuse phase transition is weakened with the increase of grain sizes. The fitted activation energy reveals the dominant defects in BCZT ceramics are oxygen vacancies, and the concentration of oxygen vacancies in the region of grain boundaries is higher than that of grains.