Preparation and Property of High-entropy (La0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 Perovskite Ceramics

Abstract

High entropy ceramic is a kind of ceramic developed based on the high entropy alloy in recent years. The appearance of high entropy ceramics provides a new concept and route for developing non-metallic materials with excellent properties. In present work, a series of high-entropy ceramics with a molar ratio of A site-(La0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 were successfully synthesized by solid state reaction. The effects of sintering temperature on phase, microstructure and electric properties were investigated. Results show that the high-entropy ceramics sintered at current temperatures are of cubic perovskite structure, and exhibit excellent insulation, with low leakage current density of J value around 10-8-10-6 A/cm2. Although the grain size increases with the increase of sintering temperature, the correlation between microstructure and dielectric properties of (La0.2Li0.2Ba0.2Sr0.2Ca0.2)TiO3 ceramics is not significant. The dielectric constant reaches its maximum value at 1350℃, with the value of 230 at the frequency of 100 Hz. Meanwhile, this high-entropy ceramic has relaxation behavior, and the relaxation peak of the permittivity moves towards high temperature with the increase of frequency.