Mixed alkali effect in borate glasses - An EPR and optical study

The mixed alkali effect is one of the classic 'anomolies' of glass science. The mixed alkali borate xNa2O-(30-x)K2O-70B2O3 (5 ( x ( 25) glasses, doped with transition metal (Cu2+ and Mn2+) and rare-earth (Gd3+) ions have been investigated, using Electron Paramagnetic Resonance (EPR) and optical absorption techniques as a function of mixed alkali content to look for the 'mixed alkali effect' (MAE ) on the spectral properties of the glasses. We observed for the first time, several spectroscopic parameters revealing MAE and the change in the properties we investigated can be linked to the structural modifications of the network resu lting from the MAE. The results obtained from these (EPR and optical) studies will be discussed in detail