EPR investigation and thermal study of yA₂O-(1-y)[0.25(WO₃)₂-0.75(P₂O₅)] (A=Li, Na) glasses

Summary

Glasses belonging to the series yA₂O-(1-y)[0.25(WO₃)_2-0.75P₂O₅] (y=0.10-0.60) are elaborated. DTA experiments reveal that the glass-network of the glasses are broken with increasing of modifier content. EPR spectra show the presence of two signals due to W⁵⁺ and Mo⁵⁺, as impuritie. The intensity of these EPR centres decreases when the concentration of A₂O increases. The variation of T_g upon the modifier content is ascribed to structural changes occurring in the matrix of these glasses.