亚纳米尺度测量界面晶格振动的方法:四维电子能量损失能谱技术  

Four-dimensional electron energy loss spectroscopy probing lattice dynamics at interfaces

作　　者：毛瑞麟 时若晨 武媚 亓瑞时 杜进隆 高鹏 MAO Rui-lin;SHI Ruo-chen;WU Mei;QI Rui-shi;DU Jin-long;GAO Peng(Electron Microscopy Laboratory,Peking University,Beijing 100871,China;International Center for Quantum Materials,Peking University,Beijing 100871,China;Department of Physics,University of California,CA,Berkeley 94704-7000,USA)

机构地区：[1]北京大学电子显微镜实验室,北京100871 [2]北京大学量子材料科学中心,北京100871 [3]加利福尼亚大学伯克利分校物理系,美国加利福尼亚州伯克利94704-7000

出　　处：《电子显微学报》2023年第5期605-614,共10页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.52125307).

摘　　要：本文介绍了近年来发展的四维电子能量损失谱(four-dimensional electron energy loss spectroscopy,4D-EELS)方法的原理及在界面晶格动力学研究方面的应用。详细阐述了四维电子能量损失谱数据采集的需求、方案设计、技术特点等,并对比了该方法与其它散射谱学方法,尤其是振动谱学技术的主要优缺点。该方法的主要特点是在具有较高能量分辨率的同时,可以分别实现较高的空间、动量分辨能力,也可以通过调整实验参数灵活地在二者间取得平衡,从而将色散测量的空间分辨率提高至纳米量级。这一方法的发展使得声子色散的测量不再依赖于中子散射、同步辐射等大科学装置,也不再局限于大单晶样品的测量,能够实现对单个纳米结构甚至单原子尺寸的界面进行色散测量。Recently,a method named four-dimensional electron energy loss spectroscopy(4D-EELS)based on scanning transmission electron microscopy has been developed and employed to study the local lattice dynamics such as interfacial phonons.Here,its principle,experiment design and technical characteristics of data acquisition are described in detail,and further compared with other vibration scattering spectroscopy method.The main features of this method include high energy resolution and the ability to achieve high spatial and momentum resolution separately.The parameters of 4D-EELS experiments can also be flexibly controlled to reach balanced resolution of space,momentum in different application scenarios,while the spatial resolution of dispersion measurement can also be improved to the order of nanometer.Then such measurements no longer rely on large-scale scientific facilities such as neutron sources or synchrotron facilities.Moreover,the high spatial resolution of 4D-EELS method also makes large-sized single-crystal samples unnecessary,enabling the measurement of phonon dispersion on single nano structure or atomic-sized heterojunctions.

关 键 词：界面物理 界面晶格振动 四维电子损失能谱学 电子显微镜 

分 类 号：O469[理学—凝聚态物理] O483[理学—电子物理学] O88[理学—物理] O771