α⁃Cu_(2)Se的显微缺陷结构

Microscopic defect structure inα⁃Cu_(2)Se

本文利用球差校正电镜对Cu_(2)Se低温α相的显微缺陷结构进行精细表征。α⁃Cu_(2)Se呈层状特征,其中Se构成了刚性亚晶格,Cu离子有序填充于{111}c晶面之间形成了交替分布的富Cu层和贫Cu层。层间滑移是导致超结构出现的主要原因。在Cu_(2)Se从高温β相到低温α相的结构转变过程中,由于对称性破缺和Se刚性亚晶格的保留,Cu离子在不同区域的有序性差异使得α⁃Cu_(2)Se中存在大量共格连接的畴结构。实验结果有助于更全面地理解α⁃Cu_(2)Se的显微缺陷结构。

The microscopic defect structure in a Cu_(2)Se low⁃temperature phase was characterized by spherical aberration correction transmission electron microscopy.α⁃Cu_(2)Se has a layered structure,in which Se forms a rigid sublattice,and Cu ions are orderly filled between{111}c crystal planes,forming the alternately distributed Cu⁃rich layers and Cu⁃deficient layers.The interlayer slip is the main cause of superstructure.During the structural transition of Cu_(2)Se fromβphase toαphase,the different ordering of Cu ions in different regions generates a large number of coherently connected domain structures inα⁃Cu_(2)Se due to the symmetry breaking and the retention of Se rigid sublattice.The experimental result contribute to a more comprehensive understanding of the microscopic defect structure inα⁃Cu_(2)Se.