Effect of initial particle size on grain microstructure of textured ferroelectric ceramics: A phase-field method and brush technique

Abstract

A phase-field model was employed to simulate the grain microstructure evolution of the textured ceramics. Textured KSr2Nb5O15 (KSN) ceramics were chosen as the research object and prepared by using acicular KSN particles as raw materials. A method combining the brush technique with the rolling process was proposed for the directional arrangement of the acicular particles. The effects of the initial particle length distribution and diameter on the grain growth behavior and electrical properties were investigated. It was found the influence of the initial particle length distribution on the grain growth rate mainly depended on its diameter. The use of coarse particles was beneficial to obtain a microstructure with a strongly anisotropic morphology and homogeneous grain size. The obtained KSN ceramics exhibited a high piezoelectric constant d33 of 68 pC/N and Curie temperature of 120 ℃, which was closely related to the grain microstructure.