界面影响BFO铁电薄膜极化翻转行为的原位电学研究  

In-situ TEM study of interface effect on polarization switching mechanism in BFO ferroelectric thin film

作　　者：陈潇忻 刘中然 李柱 李吉学[1] 田鹤[1] CHEN Xiaoxin;LIU Zhongran;LI Zhu;LI Jixue;TIAN He(Center of Electron Microscope,State Key Laboratory of Silicon Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou Zhejiang 310027,China)

机构地区：[1]浙江大学电子显微镜中心,硅材料国家重点实验室,材料科学与工程学院,浙江杭州310027

出　　处：《电子显微学报》2024年第6期627-634,共8页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金重点项目(No.U21A2067);浙江省自然科学基金重大项目(No.LD21E020002)。

摘　　要：铁电薄膜在高密度存储器等微型功能器件具有巨大的应用前景,在外场下研究铁电薄膜极化翻转机制具有重要意义。本文用原位透射电镜技术对BFO薄膜电容器的铁电极化翻转动态行为及界面因素进行了研究。原位结果观察到“面内层状”与典型“成核生长”两种铁电极化翻转模式;HAADF高分辨与高斯拟合分析结果表明界面几何构型的影响作用,界面几何曲率的不同导致局部电荷密度不同,并进一步影响局部内建电场和成核势垒,使得铁电极化翻转呈现不同的行为模式。本研究为调控铁电成核与翻转方式以及器件界面设计提供了新的见解和参考。Ferroelectric thin films have promising applications in micro-functional devices such as high-density memory.Studying the polarization switching behavior of ferroelectric thin films under an external field is of great significance.In this paper,the dynamic behavior of ferroelectric polarization reversal and interface factors of BFO thin film capacitor were investigated using in-situ TEM.The In-situ result revealed two types of ferroelectric polarization switching modes:“In-plane layer-like”and typical“nucleation growth”.The result from HAADF high-resolution and Gaussian fitting analysis demonstrated that the geometric configuration of the interface played a crucial role.Variations in the geometric curvature of the interface led to different degrees of local charge aggregation,which in turn affected the local built-in electric field and nucleation barrier,resulting in distinct ferroelectric polarization reversal behaviors.This study provides new insights and references for the regulation of ferroelectric nucleation and switching mode,as well as interface design in devices.

关 键 词：铁电薄膜 极化翻转 原位透射电镜 BFO 

分 类 号：TB34[一般工业技术—材料科学与工程] O766.1[理学—晶体学] O766.4[金属学及工艺—物理冶金] TG115.215.3[金属学及工艺—金属学]