Thermal properties of silver pyrophosphate-anomalously high glass heat capacities

Heat capacity behaviour of silver pyrophosphate has been investigated in the glassy and crystalline phases. Heat capacity of the glass is unusually large which may be of configurational origin. It is proposed that an equilibrium of complex phosphate anionic species gives rise to the observed high configurational entropies and also accounts for glass stability. Infrared spectra of the glasses which contain additional features have been used to support the presence of such equilibrium.