VARIATION OF THE DIELECTRIC-CONSTANT OF ANODIC OXIDE-FILMS ON TITANIUM WITH OXYGEN EVOLUTION

Titanium was anodized potentiodynamically in acidic solution of pH 3 ( Na2SO4 + H2SO4) in the potential region before and at oxygen evolution . The oxide film growth efficiency in the range of potential above oxy gen evolution was investigated using galvanostatic charging curves. A value of 62% for the efficiency was estimated. The conductivity charac teristics of the oxide film formed in the two regions were investigate d on the basis of the variation of the dielectric constant. Values of 18.2 and 39.7 for the dielectric constant were obtained for oxides for med in the region before and at the oxygen evolution potential, respec tively.