Glasses of xFe2O3 (l-x) Na2B4O7 for 0.3≤x≤5 mol% have been studied by means of EPR. The distribution of Fe3+ ions in the vitreous network. as isolated and connected in clusters. depends on the impurity contents in t...Glasses of xFe2O3 (l-x) Na2B4O7 for 0.3≤x≤5 mol% have been studied by means of EPR. The distribution of Fe3+ ions in the vitreous network. as isolated and connected in clusters. depends on the impurity contents in the glass. A thermal treatment inducing the Fe3+ -rich phase separation ends at the sample crystallization, when performed at about 550℃, Weathering of glasses causes a Superficial alteration of their optical properties. It enters the bulk of the glass for powdered samples. As a result of gamma irradiation pararnagnetic hole centers were detected:the BOHC. the peroxy radical and the iron hole centers展开更多
The xMnO(100-x)[2P2O5.PbO] glasses were prepared with MnO concentration being in the range of 0≤x≤50 mole fraction and were investigated by EPR spectroscopy and magneticsusceptibility measurements. Octahedral symmet...The xMnO(100-x)[2P2O5.PbO] glasses were prepared with MnO concentration being in the range of 0≤x≤50 mole fraction and were investigated by EPR spectroscopy and magneticsusceptibility measurements. Octahedral symmetric sites tetragonally distorted were detected for x≤5 mole fraction MnO. Only Mn2+ ions were identified in these glasses, involved in dipoledipole interactions展开更多
Boro-germanate glasses containing copper, i.e., xCuO(1-x)[GeO2·B2O3] subjected to gamma irradiation, were studied by means of EPR. Comparisons were made with the xCuO·(1-x)[Na2B4O7] system. Irradiation induc...Boro-germanate glasses containing copper, i.e., xCuO(1-x)[GeO2·B2O3] subjected to gamma irradiation, were studied by means of EPR. Comparisons were made with the xCuO·(1-x)[Na2B4O7] system. Irradiation induced centers were detected. These are: electron trapped at a hydrogen compensated germanium ion centers; boron oxygen hole centers and electron trapped at an oxygen vacancy centers. Strong dependence of the paramagnetic irradiation-induced centers concentration on the CuO content of the sample was evidenced.展开更多
文摘Glasses of xFe2O3 (l-x) Na2B4O7 for 0.3≤x≤5 mol% have been studied by means of EPR. The distribution of Fe3+ ions in the vitreous network. as isolated and connected in clusters. depends on the impurity contents in the glass. A thermal treatment inducing the Fe3+ -rich phase separation ends at the sample crystallization, when performed at about 550℃, Weathering of glasses causes a Superficial alteration of their optical properties. It enters the bulk of the glass for powdered samples. As a result of gamma irradiation pararnagnetic hole centers were detected:the BOHC. the peroxy radical and the iron hole centers
文摘The xMnO(100-x)[2P2O5.PbO] glasses were prepared with MnO concentration being in the range of 0≤x≤50 mole fraction and were investigated by EPR spectroscopy and magneticsusceptibility measurements. Octahedral symmetric sites tetragonally distorted were detected for x≤5 mole fraction MnO. Only Mn2+ ions were identified in these glasses, involved in dipoledipole interactions
文摘Boro-germanate glasses containing copper, i.e., xCuO(1-x)[GeO2·B2O3] subjected to gamma irradiation, were studied by means of EPR. Comparisons were made with the xCuO·(1-x)[Na2B4O7] system. Irradiation induced centers were detected. These are: electron trapped at a hydrogen compensated germanium ion centers; boron oxygen hole centers and electron trapped at an oxygen vacancy centers. Strong dependence of the paramagnetic irradiation-induced centers concentration on the CuO content of the sample was evidenced.
