Optical absorption and electron paramagnetic resonance study of -doped phosphate glasses

Abstract

We report in this paper optical absorption and electron paramagnetic resonance (EPR) results obtained on -doped phosphate glasses. Optical absorption allowed us to evaluate the crystal-field parameters , B and C. Electron paramagnetic resonance measurements indicate that ions are located in sites with low symmetry and a relatively large zero-field splitting. Both electron paramagnetic resonance and optical absorption data show that the chemical bonds of ions with the ligands are rather covalent in nature but that the ionic contribution to those bonds decreases in the order: PBa > PBaK > PBaKMg. Furthermore, it is found from this study that the crystal-field strength increases in the order: PBa < PBaK < PBaKMg.