Electron paramagnetic resonance study on phosphosilicate glasses

摘要

The phospho-silicate glass containing 10 mol% CrF2 was studied by electron paramagnetic resonance (EPR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) equipped with electron diffraction apparatus which is specified for measuring the electron diffraction pattern (EDP). EPR spectroscopy offers information about oxidation states of Cr ions and their coordination symmetry in the vitreous network. The EPR spectra of Cr3+ of glass containing 10 mol% CrF2 have revealed two essential resonance signals with effective g values at geff ? 4.93 and geff ? 2.14. Presence of the two resonances is considered as a good evidence for the presence of trivalent chromium ions of octahedral coordination in glass containing 10 mol.% CrF2. X-ray and electron diffraction measurements on sample containing 10 mol% CrF2 have confirmed that there are some crystalline phases distributed in the main glass network. TEM micrograph has revealed a heavy accumulation of crystalline species. The glass which was exposed to irradiation process has showed different EPR signal when it compared with that of unirradiated sample.