像差校正电子显微镜研究Cr2Nb中的棱柱面层错结构
章 炜1，2，杜 奎1*，叶恒强1
（1.中国科学院金属研究所沈阳材料科学国家研究中心，辽宁 沈阳110016；2.先进能源材料化学教育部重点实验室，南开大学化学学院，天津300071）
摘 要 解析具有复杂结构的材料内部缺陷特征是理解材料变形机理的前提。本文针对高温变形后的Laves相Cr2Nb，利用像差校正电子显微镜的高分辨成像技术分析Cr2Nb（-1100）棱柱面内的层错结构，在原子尺度上明确其精细构型，并辅以高角环形暗场成像技术确定每个原子的元素种类。结果表明这种层错结构特异，而且其中Cr原子的配位多面体不同于Laves相中的配位体构型，形成了畸变的CN12配位体和不常见的CN13配位体。新层错结构的发现丰富了我们对复杂结构内缺陷类型的认知。
关键词 Laves相；Cr2Nb；像差校正电子显微镜；层错
中图分类号：
文献标识码：Adoi:10.3969/j.issn.1000-6281.2020.05.001
Atomic-scale visualization of the stacking fault on prismatic planes in Cr2Nb
ZHANG Wei1，2，DU Kui2*，YE Heng-qiang1
(1.Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016；2. Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, China）
Abstract The investigation of the defect in complex-structured materials provides the basis to fully understand the mechanisms of plastic deformation. By using aberration-corrected electron microscopy, we identified an atomic-scale structure of stacking fault on (-1100) plane in Cr2Nb. The results show that the stacking fault possesses a unique structure. In this structure, Cr atom is centered either in a distorted CN12 or a CN13 coordination polyhedron, which is different from other coordination polyhedra in Laves phases. The findings enrich our knowledge on the defect types in complex-structured materials.
Keywords Laves phase；Cr2Nb；aberration-corrected transmission electron microscopy；stacking fault
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