Structural effect of thorium on the local order in a phosphate glass matrix

The influence of ThO2 addition on the local order of 2P(2)O(5). Na2O glass matrix was investigated by IR and EPR spectroscopic analyses of non-irradia ted and gamma-irradiated zThO(2)(100 - x)[2P(2)O(5). Na2O] glass samples (0 less than or equal to x < 20 mol%). After the applied gamma irradiation tr eatments, the IR spectra are not significantly modified. The as-prepared sa mples and also the unirradiated samples examined after two years do not giv e rise to any EPR signal at the room temperature. The applied gamma irradia tion treatments induce paramagnetic defects. The EPR spectra consist of dou blets attributed to an electron trapped at a nonbridging oxygen vacancy.