Evidence of Distinct Structural Clusters in Amorphous Ge(1-x)Sn(x)Se2

摘要

The structure of amorphous Ge(1-x)Sn(x)Se2 has been examined at liquid nitrogentemperatures (atmospheric pressure) and at high pressures (room temperature) using Mossbauer spectroscopy. The low temperature study shows that the fraction of Sn atoms occurring in a tetrahedrally bonded site does not change with concentration. The measurements at high pressure were made on a glass with composition Ge(0.5)Sn(0.5)Se2. The data are consistent with a hypothesis that the glasses are made up of distinct structural clusters. Two different regions of response to pressure were interpreted as a low pressure region in which the intercluster interactions were changed and a high pressure region in which the intracluster interactions were affected. Chalcogenide glasses are molecular solids and are of interest because they exhibit photo-induced changes in optical properties (1). To understand these changes, it is important to know the structure of the glasses. This paper provides measurements of site occupation at liquid nitrogen temperatures and changes in structures of the glasses when hydrostatic pressure is applied.