Mixed cation effect in xR2O-(40 − x)Na2O-50B2O3-10Bi2O3 (R = Li, K) glasses

Mass density, glass transition temperature and ionic conductivity are measured in xLi2O-(40 − x)Na2O-50B2O3-10Bi2O3 and xK2O-(40 − x)Na2O-50B2O3-10Bi2O3 glass systems with 0 ≤ x ≤ 40 mol%. The strength of the mixed alkali effect in Tg, dc electrical conductivity and activation energy has been determined in each glass system. The magnitudes of the mixed alkali effect in Tg for the mixed Li/Na glass system are much smaller than those in the mixed K/Na glasses. The impact of mixed alkali effect on dc electrical conductivity in mixed Li/Na glass system is more pronounced than in the K/Na glass system. The results are explained based on dynamic structure model.