基于EFTEM技术测定单晶SrTiO_(3)的电子非弹性平均自由程  

Determination of electron inelastic mean free path of single crystal SrTiO_(3)by EFTEM

作　　者：刘曦 蒋仁辉 王怀远 吴姗姗 郑赫 赵培丽 贾双凤 王建波 LIU Xi;JIANG Ren-hui;WANG Huai-yuan;WU Shan-shan;ZHENG He;ZHAO Pei-li;JIA Shuang-feng;WANG Jian-bo(School of Physics and Technology,Center for Electron Microscopy,MOE Key Laboratory of Artificial Micro-and Nano-structures,and Institute for Advanced Studies,Wuhan University,Wuhan Hubei 430072;Wuhan University Shenzhen Research Institute,Shenzhen Guangdong 518057;Core Facility of Wuhan University,Wuhan Hubei 430072,China)

机构地区：[1]武汉大学物理科学与技术学院,电子显微镜中心,人工微结构教育部重点实验室和高等研究院,湖北武汉430072 [2]武汉大学深圳研究院,广东深圳518057 [3]武汉大学科研公共服务条件平台,湖北武汉430072

出　　处：《电子显微学报》2023年第4期441-448,共8页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(Nos.52071237,12074290,51871169,52101021,12104345);湖北省青年拔尖人才计划;中央高校基本科研业务费专项资金(No.2042023kf0172);深圳市科创委基础研究面上项目(No.JCYJ20190808150407522).

摘　　要：材料的电子非弹性平均自由程(λ)是描述电子在材料中的输运性质的重要参数。然而通过实验技术直接获取材料的λ较为困难。本文介绍了一种基于EFTEM实验技术获取SrTiO_(3)单晶λ的方法:(1)采用聚焦离子束(FIB)技术制备了具有梯度厚度(100~800 nm)的SrTiO_(3)截面样品I,并利用EFTEM得到SrTiO_(3)薄片各个阶梯区域t与λ的比值a;(2)利用FIB将截面样品Ⅰ进行二次加工得到截面样品II,并利用透射电子显微技术(TEM)直接测量各个梯度区域的t,λ即为t与a的比值。实验中测得单晶SrTiO_(3)<001>和<110>方向的λ分别为124.7 nm和120.7 nm。研究结果对利用EFTEM技术测量λ具有重要的指导意义。The electron inelastic mean free path(λ)of a material is an important parameter to describe the transport properties of electrons in the material,but it is difficult to obtain theλvalue directly through experimental techniques.Here,a method for obtaining theλvalue of single crystal SrTiO_(3)is presented based on energy filtered transmission electron microscopy(EFTEM):(1)SrTiO_(3)cross⁃section sample I with a gradient thickness of 100-800 nm was prepared by focused ion beam(FIB),and the ratio a of each step region t toλof SrTiO_(3)sheet was examined by EFTEM.(2)The cross⁃section sample II with the thickness of sample I was prepared by FIB,and the t of each gradient region was measured directly TEM.Theλvalue of SrTiO_(3)along<001>and<110>is 124.7 nm and 120.7 nm,respectively.The result have an important guideline for the measurement ofλbased on EFTEM technique.

关 键 词：SrTiO_(3) 电子非弹性平均自由程 厚度测量 能量过滤透射电子显微技术 透射电子显微学 

分 类 号：TG115.215.3[金属学及工艺—物理冶金] O766.1[金属学及工艺—金属学] O799[理学—晶体学] O722.4[电子电信—物理电子学] O739TN16