Electrical relaxation and ageing effect in AgPO3 glass

Abstract

Abstract The complex relative permittivity of silver phosphate glass has been measured in the temperature range 200–400 K, and frequency range 12–105 Hz. Two relaxation processes occur within the glass. Both are observed in the electrical modulus spectrum but only the low-temperature, or faster, process in the loss spectrum. The faster process is attributed to the motion of Ag+ ions that form ion pairs with the phosphate chains and the slower to the local motions of the chain segments. Both indicate the presence of loosely packed regions in the disordered matrix. Annealing increased the strength of the faster process but decreased that of the slower process in a manner qualitatively similar to that observed on cooling the glass. In molten AgPO3 at 790 K, the faster process has the same rate as the viscoelastic modes of PO− 4 chains and, therefore, only one peak is observed in the Brillouip scattering at 790 K. AgPO3 glass behaves like a weak electrolyte.