PHASE-TRANSITION IN BIVO4

Monophasic zircon-type tetragonal BiVO4 was prepared by a new co-preci pitation method that employs accurate control of pH and temperature. T he highly crystalline phase converts irreversibly to its monoclinic is omorph when heated between 350 and 400 degrees C. Mechanical grinding at room temperature also resulted in the tetragonal BiVO4 to transform irreversibly to the monoclinic form. The amount transformed was found to be dependant on the duration of grinding.