Calculation of ionic conductivity activation energies in ionic oxide glasses from spectroscopic data

Activation energies for ionic conduction in inorganic oxide glasses are related to cation-motion vibrational band frequencies obtained from the far-infrared spectra of the glasses. The pseudo free ion approach is considered and a closely related formalism developed using vibrational energetics for the ion and its site, is employed. It leads to good correspondence between calculated and observed quantities and to the origin of the relationship of the ion motion distance to the 'critical' vibrational amplitude. Comparisons of the calculated and observed quantities are presented for M2O-P2O5 glasses, M = Li(+), Na(+), Rb(+), Ag(+), and for a number of vitreous M2O-xSiO2 systems.