Free‐Volume Extended Defects in Structurally Modified Ge–Ga–S/Se Glasses

Abstract

Herein, transformation of free‐volume extended defects in selected chalcogenide glasses caused by thermal annealing for 10, 25, and 50 h is studied. For 80GeSe2–20Ga2Se3 as well as for GeS2–Ga2S3 glasses with different GeS2 and Ga2S3 contents (80GeS2–20Ga2S3, 82GeS2–18Ga2S3, 84GeS2–16Ga2S3), positron annihilation lifetime spectroscopy and Doppler broadening of annihilation radiation methods are applied. By analyzing the positron annihilation lifetime spectra decomposed into two components, it is shown that the observed changes in the second defect‐related component for the 80GeSe2–20Ga2Se3 glasses confirm the agglomeration of free volumes in the initial stage of annealing (10 h) with further fragmentation (25 h) and shrinkage (50 h). Increased content of Ge‐related subsystem in the GeS2–Ga2S3‐based glasses results in the agglomeration of free‐volume defects in the 82GeS2–18Ga2S3 glasses with their further expansion in the 84GeS2–16Ga2S3 matrix.