Evaluation of dielectric and piezoelectric behavior of unpoled and poled barium titanate polycrystals with oxygen vacancies using phase field method  

作　　者：Fumio Narita Takuya Kobayashi Yasuhide Shindo 

机构地区：[1]Department of Materials Processing,Graduate School of Engineering,Tohoku University,Aoba-yama 6-6-02,Sendai,Japan

出　　处：《International Journal of Smart and Nano Materials》2016年第4期265-275,共11页国际智能和纳米材料杂志（英文）

基　　金：This work was supported by JSPS KAKENHI Grant Number 16H04227.

摘　　要：This article studies the dielectric and piezoelectric behavior of unpoled and poled barium titanate(BaTiO_(3))polycrystals with oxygen vacancies.A phase field model is employed for BaTiO_(3) polycrystals,coupled with the time-dependent Ginzburg–Landau theory and the oxygen vacancies diffusion,to demonstrate the interaction between oxygen vacancies and domain evolutions.To generate grain structures,the phase field model for grain growth is also used.The hysteresis loop and butterfly curve are predicted at room and high temperatures.The permittivity,and longitudinal and transverse piezoelectric constants of the BaTiO_(3) polycrystals are then examined for various grain sizes and oxygen vacancy densities.

关 键 词：MESOMECHANICS phase field method ferroelectric ceramics piezoelectric property smart materials and structures 

分 类 号：O73[理学—晶体学]