Dielectric SrTiO3 mesocrystal derived from a H2Ti4O9·H2O single crystal

Abstract

Strontium titanate (SrTiO3, ST) is a typical paraelectric material that has been widely used in many fields as a dielectric material and an energy-storage material, especially in the electronics industry, due to its excellent dielectric properties. Herein, we report the preparation of pure ST polycrystal powder with uniform granules by the solvothermal treatment of layered titanate H2Ti4O9·H2O (HT) and Sr(OH)2·8H2O as the raw materials. The effects of specimen morphology and electric field strength on the electrical properties of ST ceramics were investigated by studying their responses to heat treatment at various temperatures. The results show that pure ST mesocrystals, nanoparticles, and ceramics were successfully prepared. The ST ceramics show a rare bimodal phenomenon and strong dielectric response, which is due to the specimens containing two forms of ST crystal structure, namely the traditional ST polycrystal and a rare ST mesocrystal. When sintered at 900 °C, the ST ceramic exhibited good electrical-response performance due to the uniform particle morphology of the specimen and a large electric field strength at 2 kV. This study demonstrates the influence of particle morphology and electric field strength on the electrical properties of ceramics and lays the foundation for the development of multifunctional oxide ceramics with excellent electrical properties.