正电子湮没符合多普勒展宽技术的材料学研究进展  

Research progress of coincidence Doppler broadening of positron annihilation measurement technology in materials

作　　者：叶凤娇 张鹏[1] 张红强 况鹏[1] 于润升[1] 王宝义[1] 曹兴忠[1] Ye Feng-Jiao;Zhang Peng;Zhang Hong-Qiang;Kuang Peng;Yu Run-Sheng;Wang Bao-Yi;Cao Xing-Zhong(Multidisciplinary Research Center,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院高能物理研究所,多学科研究中心,北京100049

出　　处：《物理学报》2024年第7期62-81,共20页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2019YFA0210002);国家自然科学基金(批准号:U1732265,12175262,11575205,11875005,11775235)资助的课题。

摘　　要：正电子湮没技术是研究材料微观结构的一种原子尺度表征方法,通过分析正电子湮没行为可以得到湮没位点处局域电子密度和原子结构信息.近年来,正电子湮没谱学技术已经发展成为优于常规手段的特色表征技术,其中符合多普勒展宽技术在研究缺陷附近的电子和原子结构方面具有独特优势,商谱曲线中高动量区域形状的变化反映了正电子湮没位点周围的元素信息.在常规符合多普勒展宽技术发展基础上,能量可调的慢正电子束流符合多普勒展宽技术在获取表面微观结构的深度分布信息上展示出独特的作用,同时也弥补了常规符合多普勒展宽技术只能表征体材料中缺陷环境的不足.本文结合国内外相关进展,综述了符合多普勒展宽技术在各类材料中的研究进展:1)合金中空位型缺陷和纳米沉淀的演化行为;2)半导体中晶格空位与杂质原子的相互作用;3)氧化物中氧空位和金属阳离子浓度的变化.除此之外,在聚合物中自由体积孔洞的大小、数量及分布的估算表征领域中,符合多普勒展宽技术也逐步得到应用.Positron annihilation technique is an atomic-scale characterization method used to analyze the defects and microstructure of materials,which is extremely sensitive to open volume defects.By examining the annihilation behaviour of positrons and electrons in open volume defects,local electron density and atomic structure information around the annihilation site can be obtained,such as the size and concentration of vacancies,and vacancy clusters.In recent years,positron annihilation spectroscopy has evolved into a superior tool for characterizing features of material compared with conventional methods.The coincident Doppler broadening technique provides unique advantages for examining the local electronic structure and chemical environment(elemental composition)information about defects due to its effectiveness describing high momentum electronic information.The low momentum portion of the quotient spectrum indicates the Doppler shift generated by the annihilation of valence electrons near the vacancy defect.Changes in the peak amplitudes and positions of the characteristic peaks in the high momentum region can reveal elemental information about the positron annihilation point.The physical mechanism of element segregation,the structural features of open volume defects and the interaction between interstitial atoms and vacancy defects are well investigated by using the coincidence Doppler broadening technology.In recent years,based on the development of Doppler broadening technology,the sensitivity of slow positron beam coincidence Doppler broadening technology with adjustable energy has been significantly enhanced at a certain depth.It is notable that slow positron beam techniques can offer surface,defect,and interface microstructural information as a function of material depth.It compensates for the fact that the traditional coincidence Doppler broadening technique can only determine the overall defect information.Positron annihilation technology has been applied to the fields of second phase evolution in irradiate

关 键 词：符合多普勒 电子动量 元素分布 微观缺陷 

分 类 号：TB303[一般工业技术—材料科学与工程]