Structural, thermal and conductive properties of Bi4-xMxV2O11 (M = La, Gd; 0 <= x <= 0.4) compounds

Abstract Bi 4− x M x V 2 O 11 (M = La, Gd) was prepared by solid state reactions. The amount of La and Gd in the (Bi 4− x M x V 2 O 11 ) was varied in the range of (0 ⩽  x  ⩽ 0.4). The addition of La and Gd to Bi 4 V 2 O 11 electrolyte was found to stabilize the β crystalline phase for x  ⩽ 0.3. In addition, the phase transition corresponding β- to γ-phases are evident in the ionic conductivity plots as well as in XRD, DSC profiles of x  ⩾ 0.3 samples. The highest ionic conductivity was observed in Bi 3.9 La 0.1 V 2 O 11 and Bi 3.8 Gd 0.2 V 2 O 11 samples in the range of 10 −3 –10 −4  S/cm for 700–500 °C. These results were supported by impedance spectroscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC).