Ukrainian Journal of Physical Optics 

¹Institute of Physical Optics, 23 Dragomanov Str., 79-005 L’viv, Ukraine, 
²Department of Physics, Academy of Bydgoszcz, 11  Weyssenhoff Sq., 85-072 Bydgoszcz, 85-072, Poland
³Dating Laboratory, University of Helsinki, POB 64, Helsinki, Finland

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Thermally stimulated luminescence (TSL) and electron spin resonance (ESR) spectra of X-, g- and b-irradiated glasses with garnet (Ca3Ga2Ge3O12), Ca-gallogermanate (Ca3Ga2Ge4O14) and Ca3Ga2O6 compositions have been investigated and analysed. X- and g-irradiation of the Ge-containing glasses induces simultaneously electron and hole paramagnetic defects, stable at room temperature, whereas the same irradiation of glasses with Ca3Ga2O6 composition yields only in stable hole paramagnetic defects. The electron defects are assigned to ensembles of E` (Ge) centres with different local environments. The hole defects belong to ensembles of O- centres, localised at different non-bridging oxygens of the glass network. The pronounced TSL glow curves in the g- and X-irradiated Ge-containing glasses peaked at about 280 C are attributed to recombination of the E` (Ge) centres. The TSL glow curves with the maximum near 230 C in the g- and X-irradiated Ge-containing glasses and the glass and ceramics with Ca3Ga2O6 composition are related to recombination of the O- centres. The TSL glow curve peaked in the vicinity of 380 C observed in the g- and X-irradiated glasses with Ca3Ga2O6 composition could be assigned to recombin-ation of non-paramagnetic defects. No TSL glow curves are observed in the b-irradiated Ge-containing glasses, whereas the TSL glow curves with the maxima at about 120, 220 and 380 C are peculiar for the glass and ceramics with Ca3Ga2O6 composition. The activation energy for the b-induced defects is estimated and their models are discussed.

Keywords: CaO-Ga2O3-GeO2 glasses, radiation-induced defects, TSL, ESR, E` (Ge) centre, O- centre

PACS: 42.70.Ce, 78.60.Kn, 76.30.Mi

doi 10.3116/16091833/6/2/55/2005