Hydrothermal, Hydrothermal-Electrochemical and Electrochemical Synthesis of Highly Crystallized Barium Tungstate Films

Abstract

Highly crystallized polycrystalline films of BaWO 4 have been synthesized on tungsten metal substrates by hydrothermal-electrochemical and electrochemical methods from room temperature to 200 °C. The hydrothermal method did not produce a film because only discrete BaWO 4 particles appeared on the tungsten substrate. The crystallization of BaWO 4 was characterized by three-dimensional nucleation and growth behaviors. In the case of the electrochemical method, an amorphous tungsten oxide film formed after the BaWO 4 film formation, while the hydrothermal-electrochemical method did not produce an amorphous film.