Effect of network structure on dynamics of lithium ions in molybdenum phosphate mixed former glasses

In this work we have studied the effect of network structure on the transport properties of Li2O-P2O5-MoO3 mixed former glasses. We have used Fourier Transform Infrared (FTIR) and Raman spectroscopy to study the network structure. We have measured ac conductivity and dielectric spectra for a wide range of temperature and frequency. We have observed that the conductivity increases and the activation energy decreases with the increase of Li2O content in the composition. The time temperature superposition has been verified using the scaling formalism of the conductivity spectra. We have calculated microscopic lengths of ion dynamics such as the characteristic mean square displacement of mobile ions and the spatial extent of localized motion within the framework of the linear response theory and correlated them with the ion transport properties. Also we have given a qualitative description for the correlation of the ionic transport with the relative strengths of structural units.