Electronic Spectra of Pr^3^+ Doped Mixed Alkali Borate Glasses

An investigation of the optical absorption spectra of 1 mol% $Pr_2O_3$ in mixed alkali borate glasses of the type $xNa_2O. (30-x) K_2O.69B_2O_3. 1Pr_2O_3$ (x=5,10,15,20 and 25) is presented