Phase transition changes in Bi4CexV2−xO11−(x/2)−δ system

Samples of Bi4CexV2−xO11−(x/2)−δ were prepared by the conventional solid-state reactions. The phase transition changes were studied by combining results obtained from high temperature X-ray powder diffraction (HT-XRPD), differential thermal analysis (DTA) and conductivity measurements. For x = 0.15 composition, the phase transitions; α ↔ β and β ↔ γ were clearly evident in the temperature ranges 423–450 and 533–550 °C, respectively. Although no subtle change in variation of the unit cell parameters was observed for x = 0.25 composition, the Arrhenius plot and DTA thermogram showed evidence of γ′ ↔ γ phase transition in the temperature range 450–500 °C.