狭缝阵列法产生准贝塞尔电子束用于HAADF-STEM成像研究  

Generation of quasi electron Bessel beams by slit arrays for HAADF-STEM imaging

作　　者：林宇铖 陈鑫铠 张婉如 田鹤[1] LIN Yucheng;CHEN Xinkai;ZHANG Wanru;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670-676,共7页Journal of Chinese Electron Microscopy Society

基　　金：国家重点研发计划(No.2017YFB0703100);浙江省自然科学基金重大项目(No.LD21E020002)。

摘　　要：贝塞尔电子束具有的自愈性和无衍射性使其在电子显微成像和电子断层扫描等领域中具有独特优势。本文制备了狭缝阵列光阑并安装在透射电子显微镜中用于产生具有自愈性和无衍射性的准贝塞尔电子束(Bessel beams,BBs)。与单狭缝法相比,狭缝阵列光阑(slit arrays aperture,SAA)法提高了BBs的中心束强度并降低衍射旁瓣影响。与普通会聚束相比,BBs被用于扫描透射模式(scanning transmission electron microscopy,STEM)下的高角环形暗场像(high-angle annular dark-field,HAADF),成像时具有更大景深并能修正强度与厚度间的非线性阻尼效应,因而BBs将在易损伤样品拍摄和电子断层扫描中拥有较好的应用前景。Bessel electron beams have unique advantages in electron microscopy imaging and tomography due to its self-healing and non-diffraction properties.The slit arrays aperture is prepared and installed in transmission electron microscope to generate quasi Bessel beams(BBs).In this paper,it is verified that the slit arrays method produces non-diffracting and self-healing electron beams.Compared with the single slit method,the center beam intensity of BBs is increased and the influence of side lobes intensity is reduced.It is proved that BBs has larger depth of field and can correct the nonlinear damping effect between intensity and thickness when used in HAADF-STEM imaging compared with ordinary converging beam.Therefore,BBs will have a good application prospect in the imaging of vulnerable samples and electron tomography.

关 键 词：狭缝阵列光阑 贝塞尔电子束 HAADF-STEM 

分 类 号：TB383[一般工业技术—材料科学与工程]