AI 中文总结
研究利用潜在空间框架从原位4D-STEM衍射数据绘制砷化镓再结晶轨迹，通过卷积自动编码器和无监督聚类构建相轨迹模型，揭示不同温度下再结晶区域及结构变化，还识别出再结晶前的非晶模式，为再结晶启动提供新认识。
AI 中文摘要
无序固体中的再结晶通过一系列局部结构重排进行，传统衍射分析难以解析。在非晶和部分有序材料中，漫散射、短程有序和缺陷介导的对称性出现的细微变化编码了有序化启动和传播的途径。本文引入了一个潜在空间框架，直接从原位4D-STEM衍射数据中绘制这些途径。卷积自动编码器提供结构基序的紧凑表示，无监督聚类识别反复出现的微观结构状态。通过跟踪这些状态随温度的变化，构建相轨迹模型，揭示再结晶景观的拓扑结构。应用于离子辐照的砷化镓，该方法揭示了两个不同的再结晶区域。低温下，再结晶以生长为主，由非晶和晶体状态的持续存在主导。高温下，转变景观重新组织。潜在空间表示还识别出再结晶之前具有弱对称特征的非晶模式，揭示了传统描述符未捕获的有序化结构前体，为再结晶的启动提供了新见解。
英文摘要
Recrystallization in disordered solids proceeds through a sequence of local structural rearrangements that are difficult to resolve using conventional diffraction analysis. In amorphous and partially ordered materials, subtle variations in diffuse scattering, short-range order, and defect-mediated symmetry emergence encode the pathways through which ordering initiates and propagates. Here, we introduce a latent space framework for mapping these pathways directly from \textit{in situ} 4D-STEM diffraction data. A convolutional autoencoder provides a compact representation of structural motifs, and unsupervised clustering identifies recurring microstructural states, including amorphous, paracrystalline, crystalline, twinned, and hybrid intermediates. By tracking these states across temperature, we construct phase trajectory models that reveal the topology of the recrystallization landscape, including metastable basins, branching pathways, hybrid states, and temperature-dependent reorganizations of accessible states. Applied to ion irradiated GaAs, this approach uncovers two distinct recrystallization regimes separated by a transition near 250\textdegree{}C. At low temperature, recrystallization is growth-dominated and dominated by the persistence of amorphous and crystalline states. At high temperature, the transformation landscape reorganizes: hybrid and faulted states become metastable precursors to twinning, polycrystalline regions stabilize, and twinned structures emerge as dominant end states. The latent space representation also identifies amorphous patterns with weak symmetry signatures that precede recrystallization. This reveals structural precursors to ordering that are not captured by conventional descriptors give new insights into how recrystallization is initiated.
Comments22 pages
