Preparation of MgxZn1-xO Resistive Switching Film by Sol-gel Method and its Corrosion Behavior in 3.5 wt% NaCl solution

MgxZn1-xO resistive switching films with different Mg content were prepared on SS 304 stainless steel by the sol-gel method. The morphology, structure and composition of the films were analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and XPS techniques. The semiconductor type and corrosion resistance of MgxZn1-xO films were studied by Mott-Schottky curve, polarization curve and electrochemical impedance spectroscopy (EIS) methods. The prepared MgxZn1-xO resistive switching films are composed of fine equiaxed grains, with the grain size and lattice constant of the films decreasing on increasing the Mg content. The MgxZn1-xO films are belonged to n-type materials and the oxygen vacancy concentration in the films is enhanced with the Mg content. The MgxZn1-xO resistive switching films in 3.5%NaCl solution exhibit a lower corrosion current density and a higher polarization resistance than that of SS304 stainless steel, and the corrosion resistance is decreased on enhancing the content of the Mg element. During the immersion process, the O-2 molecules dissolve in the solution could be absorbed on the film and react with the oxygen vacancies, thus, the concentration of oxygen vacancy in the film is reduced and the corrosion resistance of film is subsequently improved. After immersion test, the concentration of the oxygen vacancy in the film could be restored again by the application of the positive voltage on the corroded films.