Paramagnetic defects in germanium sulfur glasses

Abstract

ESR-studies were conducted at 9.5 GHz on GeS 2±x glasses (x=0,0.1). Glasses were melted at 683°C, 789°C and 895°C in Vycor tubes which were evacuated and sealed before fusion. The ESR-spectra of the virgin glasses are characterized by a narrow symmetric (g=2.0037, ΔH pp=3G, A-component) and a broad asymmetric line (g=2.0113, ΔH pp=17G, B-component). The narrow line was not detected in the GeS 2±x glasses fused at 895°C and in the GeS 2.1 glass fused at 796°C. The narrow line intensity of the sulfur deficit glass is approximately two times the corresponding intensity of the stoichiometric and sulfur excess glass. The intensity of the asymmetric line is negligibly small in the GeS glasses fused at 638°C. It dominates in the spectra of the GeS glasses fused at 789°C, and triples in the GeS glasses fused at 895°C. Structural models for the defect centers which cause the detected lines have not yet been developed by us.