Fano׳s antiresonance and crystal-field study of Cr3+ in metaphosphate glasses

This work is devoted in first part to a study of the features observed on the 4T2g (4F) absorption band of phosphate glasses containing Cr3+. These features results from interaction of the 2Eg (2G) and 2T1g (2G) sharp levels with the vibrationally broadened 4T2g (4F) quasi-continuum via spin-orbit coupling and have been analyzed in the frame of the Fano׳s antiresonance model. In second part, the electronic structure of Cr3+ ion occupying Oh site symmetry in the phosphate glasses is determined by the crystal-field analysis. The influence of the different oxides (Na2O, PbO, ZnO) on the spectroscopic properties of Cr3+ is evaluated. In metaphosphate glasses, we found that Na2O and PbO oxides act as glass modifiers while ZnO enters the glass forming network.