Ge xS 1− x glasses. Defects, density and structure

Abstract

The density, X-ray scattering and ESR ofGe x S 1− x glasses within0.10 ⩽ x ⩽ 0.44 have been measured. The region of compositions in question is subdivided into three intervals: 0.10 ⩽ x ⩽ 0.325, 0.325 ⩽ x ⩽ 0.30and0.30 ⩽ 0.44 according to the types of paramagnetic centers (PC) and the specific features of the concentration dependences of the experimental quantities under study. It is found that the density, the PC concentration and the features of the radial distribution functions are correlated in each interval. The concentration dependence of the relative amount of two types of PC is the first interval is obtained. The influence of γ-irradiation at 300 K upon the structure and concentration of PC is studied. It is found that under γ-irradiation the amount of PC either increases (first and second interval) or decreases (third interval) and the unpaired spin density is redistributed among different types of structural defects. New types of PC do not arise under γ-irradiation. In the framework of the structural chemical analysis the models of structural units and their transformation with glass composition are suggested. Based on the proposed model for the glass network, the experimental data are analyzed.