Abstract Ge-Sb-Te based phase change alloys are currently used in optical data storage and are regarded as promising candidates to replace Flash memories. Detailed knowledge of structural defects in these materials is crucial for further understanding of the switching mechanisms, e.g., in recently proposed interfacial phase change memory. In the present work, atomic structure and dynamics of layered defects frequently reported in van der Waals bonded Ge-Sb-Te based materials and GeTe Sb 2 Te 3 based superlattices are studied using advanced transmission electron microscopy. It is shown that the defects are confined into two atomic layers of GeSb and Te and represent localized stacking faults. In situ experiments revealed that the GeSb and Te bilayers can be easily reconfigured into such bilayer stacking faults with subsequent formation of a new van der Waals gap, indicating a mechanism of structural reconfiguration of building blocks in layered Ge-Sb-Te compounds. Overall the results of the present work shed insights into the dynamics of van der Waals gaps rearrangement and mechanism of the layer exchange process in layered functional chalcogenide compounds, also relevant for an understanding of switching mechanisms in interfacial phase change alloys.

中文翻译：

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范德华层状Ge-Sb-Te基材料中层状缺陷的原子结构和动态重构

摘要 Ge-Sb-Te 基相变合金目前用于光学数据存储，被认为是替代闪存的有希望的候选者。详细了解这些材料中的结构缺陷对于进一步了解开关机制至关重要，例如在最近提出的界面相变存储器中。在目前的工作中，使用先进的透射电子显微镜研究了范德华键合 Ge-Sb-Te 基材料和 GeTe Sb 2 Te 3 基超晶格中经常报道的层状缺陷的原子结构和动力学。结果表明，缺陷被限制在 GeSb 和 Te 的两个原子层中，并代表局部堆垛层错。原位实验表明，GeSb 和 Te 双层可以很容易地重新配置为这种双层堆垛层错，随后形成新的范德华间隙，表明层状 Ge-Sb-Te 化合物中构建块的结构重新配置机制。总体而言，本工作的结果揭示了范德华间隙重排的动力学和层状功能硫属化物化合物中层交换过程的机制，也与了解界面相变合金的转换机制有关。