Local structure and kinetics of paramagnetic defects, induced by γ-irradiation of the erbium doped Ag5Ga5Ge95S200 glasses

Defects induced by γ-irradiation in Er-free and Er-doped glasses Ag5Ga5Ge95S200 were studied using the Raman and EPR spectroscopies. It is shown that γ-irradiation causes an increase in the intensity of Raman bands related with formation of S3Ge-GeS3 structural groups. During the low-temperature annealing at temperatures of 95–145 °C, the concentration Ns of γ-induced paramagnetic centres (PC), having the axial symmetry of the g-tensor with gz = 2.0180 and gx = gy = 2.0088, is being strongly reduced and the symmetry of the environment of these centres becomes lower. Subsequent storage of annealed samples in the air for about 15 days leads to a gradual restoration of the Ns concentration. The kinetics of these processes is described taking into account both the high mobility of sulfur vacancy and the long-time relaxation of the glass structure. A correlation between the intensity of 257 cm−1 Raman band belonging to the S3Ge(Ga)-(Ga)GeS3 complex and PC characteristics is discussed. •The local structure in Er-doped Ag5Ga5Ge95S200 glasses by Raman and EPR spectroscopy was investigated.•Effect of γ-irradiation on the formation of paramagnetic centers in Ag5Ga5Ge95S200 glasses doped with various doses of erbium has been studied.•Fast and slow components were first observed in the concentration dependence of paramagnetic defects on the time of low temperature annealing.•Based on the theoretical analysis of the local structure of the glass supposed that the paramagnetic centers are Ga-VS.