This paper investigates into the unexpected nanosize Fe-enriched particles with defects incorporated, using EDS under STEM mode and atomic-resolution HAADF. The particle that locates between eutectic Mg12 Ce phase and α-Mg phase is identified as CeFe2 Si2 compound. Two types of defects are incorporated: Type-I defect is Ce-Si in a simple cubic lattice; Type-II defect is Ce in a FCC lattice. The interface between the defect-free CeFe2 Si2 and the defects is fully coherent. In addition, another two Ce/Fe/Si-enriched particles are observed, proving that the enrichment of Ce, Fe, and Si is not an accidental phenomenon. The observed formation of Ce/Fe/Si-enriched particles provides a possible explanation for the improvement in corrosion resistance and the purification effect induced by addition of rare earth elements into alloys. In addition, the present study demonstrates an advanced application of Cs-corrected HAADF by successfully directly imaging the dislocation and complex defects incorporated in the compound and by achieving a one-angstrom resolution. SCANNING 38:783-791, 2016. © 2016 Wiley Periodicals, Inc.

中文翻译：

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在 Mg-Ce 合金中观察到意外的富铁化合物：原子级 STEM 研究

本文在 STEM 模式下使用 EDS 和原子分辨率 HAADF，研究了出乎意料的纳米级富铁颗粒，其中掺入了缺陷。位于共晶Mg12 Ce 相和α-Mg 相之间的颗粒被鉴定为CeFe2 Si2 化合物。包含两种类型的缺陷：I 类缺陷是简单立方晶格中的 Ce-Si；II 型缺陷是 FCC 晶格中的 Ce。无缺陷的 CeFe2 Si2 和缺陷之间的界面是完全相干的。此外，观察到另外两个Ce/Fe/Si富集颗粒，证明Ce、Fe和Si的富集并非偶然现象。观察到的 Ce/Fe/Si 富集颗粒的形成为合金中添加稀土元素引起的耐腐蚀性和净化效果的提高提供了可能的解释。此外，本研究通过成功地直接成像化合物中包含的位错和复杂缺陷并实现一埃的分辨率，展示了 Cs 校正的 HAADF 的先进应用。扫描 38:783-791, 2016. © 2016 Wiley Periodicals, Inc.