CuSn系超结构的电子衍射与能量分析

The electron diffraction and energy analysis of CuSn superstructures

本文首先根据CuSn合金的选区电子衍射图构建出一种新的三次超结构的单胞和五次超结构η-′Cu6Sn5相与六角CuSn相的取向关系。然后对CuSn合金几种可能的超结构进行能量计算,发现晶胞中的空位占有率和优化前后几何变化率成线性关系,以及超结构中Edshammar多面体中心的多余Cu原子和同一平面Sn原子之间键长对晶胞的稳定性至关重要。

In this paper, two superstructures with three and five fold diffraction spots in the CuSn alloy were constructed directly from the selected- area electron diffraction patterns. Energy calculations of some possible superstructures of the Cu-Sn superstructures have been performed. The linear relationship between the occupancy of the vacancy positions and the ration of volume change was found. Combining with the calculations of the formation energy, it is shown that the distances between the interstitial Cu atom and the Sn atom in the same plane of the Edshammar polyhedron are crucial to the stability of the superstructures.