Synthesis, characterization and ionic conductivity of Bi2VO5

A new method of synthesis for alpha-Bi2VO5 oxide has been described in orde r to improve the structural characteristics and ionic conductivity of this material. The differential scanning calorimetry curve shows five reversible effects, three of them observed at 397-388 degrees C, 455-503 degrees C an d 778-807 degrees C on heating-cooling, are related to the alpha-->alpha', alpha'-->beta and beta-->gamma phase transitions, respectively, and the oth er two effects at 870-855 degrees C and 881-877 degrees C, are asociated wi th the melting and solidification of the sample. Impedance measurements wer e carried out under a continuous nitrogen flow to prevent the oxidation of V(IV) to V(V). The electrical response is due to both movement of oxygen io ns inside the grains and through the grain boundaries. The beta-Bi2VO5 show s a conductivity as high as 10(-1) ohm.cm(-1) at 730 degrees C.