手性畴壁对铁电薄膜电学性能调控的相场研究

项目名称： 手性畴壁对铁电薄膜电学性能调控的相场研究

项目编号： No.11502078

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 王芳

作者单位： 湖南科技大学

项目金额： 22万元

中文摘要： 随着器件微型化的发展，畴壁对铁电薄膜性能的影响越来越明显。手性畴壁是一种新型畴壁内部结构，可用于高密度信息存储，其较低的畴壁能和畴壁翻转势垒对铁电薄膜的电学性能有着重要的影响。目前，对于手性畴壁的研究尚处于起步阶段，畴壁内部结构对铁电薄膜宏观物理性能的影响尚未进行系统研究。基于此，本项目以铁电薄膜手性畴壁为研究对象，建立手性畴壁的模拟的相场模型，分析力电耦合作用对手性畴壁形成的影响；采用适当的应力场、电场、失配应变等，调控畴壁内部的极化矢量；研究手性畴壁与铁电薄膜电学性能的关联，从理论上掌握手性畴壁对铁电薄膜电学性能的调控规律，为铁电薄膜电学性能的优化奠定理论基础。

中文关键词： 铁电薄膜；手性畴壁；力电耦合效应；相场

英文摘要： Domain walls have more and more important effects on the properties of ferroelectric thin films as the miniaturation of the devices. Chiral domain wall is a new kind of internal structure of domain wall, it can be used for information storage of high density, the lower domain wall energy and barrier of domain-wall switching has an important influence on electrical properties of ferroelectric film. At present, the research of chiral domain wall is in an initial stage, the effect of internal structure of domain wall on macroscopic physical properties of ferroelectric film has not been systematically studied. Based on the above consideration, this project will focus on chiral domain wall of ferroelectric film. A phase field model of chiral domain wall simulation will be established and the effects of electromechanical coupling on the formation of chiral domain wall will be analyzed. The polarization vector in internal of domain wall will be controlled using appropriate stress field, electric field, mismatch strain. The relations between the chiral domain wall and electrical properties of ferroelectric film will be discussed, and the tuning method of chiral domain wall for electrical properties of ferroelectric films will be acquired in theory. It is desirable to provide a theoretical basis in favor of the performance of electrical properties of ferroelectric film.

英文关键词： Ferroelectric thin film;Chiral domain wall;Electromechanical coupling;Phase-field