Rev.Adv.Mater.Sci.(RAMS)
No 2, Vol. 12, 2006, pages 97-105

RADIATION-INDUCED DEFECTS IN GLASSES AND CERAMICS OF THE CaO-Ga2O3-GeO2 SYSTEM

B.V. Padlyak, H. Jungner, K. Fabisiak and S. P. Dubelt

Abstract

Electron spin resonance (ESR) and thermally stimulated luminescence (TSL) spectra of the X -, γ -, and β - irradiated glasses with Ca3Ga2Ge3O12 (garnet) and Ca3Ga2Ge4O14 (Ca-gallogermanate) compositions as well as glass and ceramics with Ca3Ga2O6 composition are presented and analysed. The X - and γ - irradiation of Ge-contained glasses at room temperature induces simultaneously stable electron and hole paramagnetic defects, whereas the same irradiation of glasses with Ca3Ga2O6 composition induces exclusively stable hole paramagnetic defects. Electron defects are assigned to ensembles of the E' (Ge) centres with different local environments and hole defects belongs to an ensemble of O- centres, localized on different non-bridging oxygen of the glass network. TSL band, peaked at about 280 °C in the γ - and X - irradiated Ge-contained glasses is attributed to recombination of the E' (Ge) centres. TSL band with maximum about 230 °C in the γ - and X- irradiated Ge-contained glasses and glass and ceramics with Ca3Ga2O6 composition is related to recombination of the O- centres. TSL band, peaked at about 380 °C in the γ -, X- irradiated glasses and ceramics with Ca3Ga2O6 composition as well as bands, peaked at 120, 220, and 380 °C in the same β - irradiated samples are assigned to non-paramagnetic radiation defects. Activation energies for β - induced defects in the glass and ceramics with Ca3Ga2O6 composition are estimated.

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