论文标题
使用基于地理信息系统的空间统计数据将本地化学和结构秩
Correlating Local Chemical and Structural Order Using Geographic Information Systems-Based Spatial Statistics
论文作者
论文摘要
通过（扫描）透射电子显微镜（S/TEM）成像分析纳米级短距离化学和/或结构阶，从根本上限制了三维样品的投影，这平均沿光束方向进行了信息。因此，从这些二维数据集确定的结构和化学之间提取统计学上显着的空间相关性仍然具有挑战性。在这里，我们应用了地理信息系统（GIS）中常用的方法来确定来自原子分辨率茎的局部化学测量与结构的空间相关性，从原子分辨率的茎上成像，对具有构图复杂的松弛剂的pb（mg $ _ {1/3} $ _ {1/3} $ nb $ _ {2/3} $ {2/3} $ $ _ $ _ $ _ {3} $（pmn）$ {2/3} $（PMN）。该方法用于确定存在的排序类型，并量化化学顺序，氧气八人体畸变和氧八人体倾斜的空间变化。然后，通过空间协方差分析评估了这些短距离有序区域之间的自相关和功能间相关性的程度，显示相关性与距离的函数。结果表明，整合用于分析显微镜数据集的GIS工具可以揭示复杂材料中化学和结构特征之间的微妙关系，这些关系在忽略其空间分布时可能会隐藏。
Analysis of nanoscale short-range chemical and/or structural order via (scanning) transmission electron microscopy (S/TEM) imaging is fundamentally limited by projection of the three dimensional sample, which averages informational along the beam direction. Extracting statistically significant spatial correlations between the structure and chemistry determined from these two-dimensional datasets thus remains challenging. Here, we apply methods commonly used in Geographic Information Systems (GIS) to determine the spatial correlation between measures of local chemistry and structure from atomic-resolution STEM imaging of a compositionally complex relaxor, Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$ (PMN). The approach is used to determine the type of ordering present and to quantify the spatial variation of chemical order, oxygen octahedral distortions, and oxygen octahedral tilts. The extent of autocorrelation and inter-feature correlation among these short-range ordered regions are then evaluated through a spatial covariance analysis, showing correlation as a function of distance. The results demonstrate that integrating GIS tools for analyzing microscopy datasets can serve to unravel subtle relationships among chemical and structural features in complex materials that can be hidden when ignoring their spatial distributions.
