Corrosion resistance of TiO₂ films grown on stainless steel by atomic layer deposition

Titanium dioxide (TiO₂) films have been deposited onto stainless steel substrates using atomic layer deposition (ALD) technique. Composition analysis shows that the films shield the substrates entirely. The TiO₂ films are amorphous in structure as characterized by X-ray diffraction. The electrochemical measurements show that the equilibrium corrosion potential positively shifts from - 0.96 eV for bare stainless steel to - 0.63 eV for TiO₂ coated stainless steel, and the corrosion current density decreases from 7.0 × 10^{- 7} A/cm² to 6.3 × 10^{- 8} A/cm². The corrosion resistance obtained by fitting the impedance spectra also reveals that the TiO₂ films provide good protection for stainless steel against corrosion in sodium chloride solution. The above results indicate that TiO₂ films deposited by ALD are effective in protecting stainless steel from corrosion.