Papers by Keyword: Mott-Schottky

Abstract: The effect of chloride ions on the passivity of titanium in sulfuric acids was investigated by potentiodynamic and potentiostatic anodizing, Mott-Schottky analysis and the point defect model (PDM). The anodizing results indicated that chloride ions facilitate the anodic passivity of titanium in sulfuric acids. Based on the Mott-Schottky analysis in conjunction with the PDM, it was shown that the donor density decreases exponentially with increasing film formation potential. Also, the results indicated that with the increasing concentration of chloride ions, the donor density decreases, while the diffusivity of the donors increases at the same film formation potential.

Abstract: In this paper, the semiconducting behavior of non-solid electrochemical state of carbon steel in acid, base and salt solutions was studied by utilizing potential-capacitance and Mott-Schottky analysis. It was pointed out that the capacitance variation of space charge layer of non-solid electrochemical state of carbon steel in different solution was different. The non-solid electrochemical state showed p-type semiconducting behavior in 5 sulfuric acid and 5 % sodium sulfate solution. However, it showed n-type semiconducting behavior in 5 % sodium hydroxide, suggesting that the space charge layer of non-solid electrochemical state of the carbon steel in different electrolytes might be asymmetric.

Abstract: For the purpose of improving the reproducibility and the semiconductor properties of chalcopyrite CuInS₂ thin film, potassium hydrogen phthalate (C₈H₅KO₄), as a complex agent, was added into the sulphate bath system. The optimum process parameter for the preparation of CuInS₂ thin film was determined by orthogonal experiment method. The effect of C₈H₅KO₄ on the composition and Mott–Schottky behavior of the as-deposited film was studied with electron dispersion spectroscopy (EDS) and alternating current (AC) measurement. It was found that the as-deposited film was p-type semiconductor with the flatband of 0.665 V and the acceptor density of 3.06×10¹⁹ cm^-3; the addition of C₈H₅KO₄ can effectively enhance the composition stability of the film and decrease its flatband potential and acceptor density.

Abstract: Cu-Ni-Fe alloy-layer was prepared by the method of copper oxide- nickel oxide mixed powder deposited on the surface of mild steel samples and then treated under high temperature and hydrogen gas atmosphere. Polarization techniques and Mott-Schottky analysis in conjunction with the point defect model (PDM) have been used to investigate the semiconductor properties of the passive films formed on the surface of Cu-Ni-Fe alloy layer in borate buffer solution at pH 8.4. The results showed that the passive film formed on the surface was more compact, highly protective with higher heating temperature. Carriers density and vacancies diffusion coefficient of the passive film formed on Cu-Ni-Fe alloys decreased with higher heating temperature. The vacancies diffusivity is about magnitude of 10-20m2•s-1 in borate buffer solution at pH 8.4.

Abstract: Effects of pH values on corrosion properties of 316L stainless steel were investigated to clarify the usability of 316L SS in circulating cooling water system. The polarization, EIS and Mott-Schottky measurements showed the superior corrosion resistance of 316L SS in the simulated cooling water solution with NaCl+Na2SO4. The Fe hydroxides and oxides products resulted in the passive film of 316L SS thicker during the cooling water convection, as the pH increased from 6.5 to 9.0.