Novel composition above the limit of Bi:Zr solid solution; synthesis and physical properties of Bi1.33Zr0.67O3+δ

This paper presents an increase to x = 0.67 of the zirconium content in the conductive Bi2−xZrxO3+δ solid solution. Complete incorporation of Zr in the βIII-Bi2O3 structure, confirmed by X-ray powder diffraction, has produced a phase with a lower volume and superior conductivity than those predicted by an earlier study. The observed βIII-δ Bi2−xZrxO3+δ phase transition around 730 °C has been characterised for the first time and shows a segregation of a mixture of predominantly γ-Bi2O3 and approximately 30% of the ZrO2, before total reincorporation of the Zr in the high temperature δ-phase.