Preparation of Barium Titanate Thin Film on Titanium-Deposited Glass Substrate by Hydrothermal-Electrochemical Method

Abstract

Well-crystallized polycrystalline barium titanate thin films have been prepared at sufficiently low temperatures by the hydrothermal-electrochemical reaction on titanium-deposited glass substrates. The reaction was carried out in 0.1-0.5N Ba(OH)₂ solutions at temperatures of 100°-200°C and under saturated vapor pressures, using a titanium-deposited glass substrate for anode and a Pt plate for cathode and applying an electric current galvanostatically up to 18mA/cm². The BaTiO₃ film was lustrous and dense. The thickness of the film estimated from the weight change increased from 70 to 300nm with treatment time from 10 to 60min at 200°C in 0.5N Ba(OH)₂ solution with the current density of 15mA/cm². The adhesion of the BaTiO₃ film to the glass substrate was so strong that no exfoliation was observed. Similar BaTiO₃ thin films with thickness less than 70nm were formed under hydrothermal conditions without electricity.