FTIR investigation and mixed cation effect of Li2O-BaO-B2O3 glasses

FTIR, density and electric conduction investigations have been carried out on the glasses xBaO⋅(30-x)Li2O⋅70B2O3 (0 ≤ x ≤ 30 mol%) and xBaO⋅(40-x)Li2O⋅60B2O3 (0 ≤ x ≤ 40 mol%). The fraction N4 of four coordinated boron atoms does not change with x and its value is around that of related binary glasses. The behavior of glasses as mixed matrices is observed in the dependence of N4, D and Vm on composition. Mixed modifier effect is observed as maxima in the activation energy for electric conduction. The maxima appear at compositions of nearly equal concentration of Li+ and Ba2+ ions. It is deduced that the mixed cation effect might be correlated with the concentration of modifier ions, rather than the modifier oxide.