Crystal structure and atomic arrangement of delta-phase Sb-Te binary alloy

Abstract

The composition modulated Sb-Te binary thin films deposited by a RF sputtering method on SiO2/Si substrates annealed through a rapid thermal annealing process and conducted a high-resolution transmission electron microscopy (HR-TEM) study in order to investigate the atomic arrangement of the delta-phase Sb-Te binary alloys which contain Te from 16 to 37 at. %. Through the comparison with HR-TEM image and diffraction patterns viewed along (2110) and (10 10) direction, we have revealed that the delta-phase Sb-Te alloy crystallized into P (3) over bar m1 or R (3) over barm space group whether the number of layers is the multiple of three or not. We also expect from analogous Bi-Te system in earlier reports that as the Sb/Te ratio increases, total number of Sb layers in a unit cell increases. Therefore, based on above result, we suggested the atomic arrangement model composed of appropriate Sb-2 and Sb2Te3 layer and obtained simulated images of < 2110 > zone axis.