Characterisation and stability of the fast ion conductor (Bi2O3)1-x(PbO)x

Abstract

β-(Bi1-xSbx)8Pb5O 17 has been shown to have very high oxygen-ion conductivity at temperatures as low as 600°C; 1 s/cm has been reported in the literature. This paper describes how the material can be characterised using high temperature Raman spectroscopy. The effect of increasing x allows for a broadening of the peaks in the Raman spectra and a shift towards lower wavenumber. This can be explained in terms of the Sb atom deforming the room temperature tetragonal β-structure and an incipient phase change in the high temperature β-phase. This paper also describes the effect of low oxygen partial pressure on the sample. In general, as x increases, the width of the ionic domain, and hence the low Po2 stability, increases down to approximately Po2 = 10-13 atmospheres. Below this dopant concentration, the stability again reduces.