High Temperature Raman Spectra of Bi8Pb5O17

Abstract

We have performed high temperature Raman spectroscopy (25-600 degrees C) on the fast ion conductor, Bi8Pb5O17, after different heat treatments. The BCC beta Bi8Pb5O17 cannot be stabilized to room temperature and reverts to the tetragonal beta(2)-phase when quenched. This is seen in the Raman spectra (either on heating or cooling) as a shift in the strong band at 118 cm(-1) for the beta-phase to 147 cm(-1) for the beta(2)-phase. However, when the sample is quenched from the intermediate region, an intermediate phase is stabilised, given by an extra unknown peak at 127 cm(-1).