Raman and Infrared Spectral Investigations of Superionic HNaZnP2O7 and HNaPbP2O7

The Raman and FTIR spectra of superionic HNaPbP2O7 and HNaZnP2O7 were recorded and analysed. The appearance of P-O symmetric stretching modes with slight differences in band position indicates that the crystal structure of the both the compounds were identical. The non-coincidence of majority of the IR and Raman bands agree with the centrosymmetric space group and the P2O74− anions in both the compounds have a non-linear P-O-P bridge configuration. Spectral bands indicate that an eclipsed configuration in HPbZnP2O7 for the P2O74− anions. The presence of protons attached to an oxygen atom of P2O74− ion is confirmed by the appearance of OH vibrations.