Microwave dielectric spectroscopy and dynamical processes in superionic glasses

The dynamical response of ionic glasses can be accurately characterized, in terms of Frequency dependent conductivity, by dielectric spectroscopy techniques. Performing measurements on superionic vitreous conductors in the microwave Frequency region, it has been discovered that the dispersive behaviour of the conductivity obeys a double power law. Model considerations associate the two power law contributions at low and high frequencies respectively with translational and localized ionic hopping processes, characterized by different activation energies. In the present study on pure and doped silver phosphate glasses, experimental evidence is found that the power law exponents assume constant values, independent of the exact glass composition, and remarkably similar to those obtained for other superionic glasses.