Electrical conductivity and micro-Raman scattering studies of ionic conduction in Li1−xHxIO3 solid solutions

Li1−xHxIO3 solid solutions have been investigated by ac electrical conductivity and micro-Raman techniques, for x≤0.32. The presence of protons leads to a continuous reduction of the anisotropic intrinsic conduction of the system. The in-plane conduction mechanism would be by Li+ vacancy hopping, while a mixed process by interstitial Li+ and H+ would account for the conduction along the c-axis. The solid solutions undergo the same phase transition sequence as the pure crystal, but the presence of the protons shifts the transition temperatures to lower values. Micro-Raman spectroscopy has been successfully introduced to demonstrate that proton mobility occurs preferentially along the c-axis.