Chemical ordering in Ge₂₀Se_80-XIn_X glasses

Abstract

Bulk glasses of Ge-Se-In have been prepared by quenching the melt and have been subjected to thermal crystallization and X-ray structure analysis of devitrified materials. These glasses show a transformation from a single-stage to a double-stage crystallization with respect to composition. The present investigations indicate that these materials are structurally inhomogeneous at a molecular level, in which In₂Se₃ microclusters are dispersed in the Ge-Se matrix. These results are discussed using the chemical threshold in glasses.