Hydrothermal, hydrothermal-electrochemical and electrochemical synthesis of highly crystallized barium tungstate films

Highly crystallized polycrystalline films of BaWO4 have been synthesized on tungsten metal substrates by hydrothermal-electrochemical and electrochemical methods from room temperature to 200 degrees C. The hydrothermal method did not produce a film because only discrete BaWO4 particles appeared on the tungsten substrate. The crystallization of BaWO4 was characterized by three-dimensional nucleation and growth behaviors. In the case of the electrochemical method, an amorphous tungsten oxide film formed after the BaWO4 Blm formation, while the hydrothermal-electrochemical method did not produce an amorphous film.