Anodic Alumina Films Prepared by Powerful Pulsed Discharge Oxidation

By Lisenkov, Aleksey D.; Salak, Andrei N.; Poznyak, Sergei K.; Zheludkevich, Mikhail L. & Ferreira, Málrio G. S.
Published in The Journal of Physical Chemistry C NULL 2011

Abstract

A novel powerful pulsed discharge anodization technique has been applied to prepare dense, homogeneous oxide films of 16 -180 nm thick on aluminum surface. The Volta potential difference (VPD) of the obtained films was studied by scanning Kelvin probe force microscopy. The VPD value was measured as a function of the film thickness and was compared with the similar dependences for the anodic alumina films prepared by the conventional galvanostatic and potentiostatic methods. The anodic films present polarization because of the embedded charges localized near the film interfaces. It was shown that despite the apparent differences in the respective anodization processes, the pulsed discharge films demonstrate the magnitude of polarization which is entirely comparable with that of the conventional anodic alumina films of the same thickness. At the same time, the pulsed discharge films are characterized by more uniform surface structure and electrical properties. The characteristic features of the films such as their fast growth and homogeneity have been considered in terms of the processes occurring at the powerful pulsed discharge.

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