The electronic properties of sputtered chromium and iron oxide films

The semiconducting properties and electrochemical behaviour of thin chromium and iron oxide films produced by sputtering were investigated by capacitance and photoelectrochemical measurements. The films were deposited onto various Substrates and submitted in some cases, to a thermal treatment. It appears that sputtered chromium oxide on iron Substrate reveals both types of semiconductivity (p and n) and that the thermal treatment enhances the n-type character. Finally, a study is developed using a duplex film formed by sputtered layers of chromium and iron oxides. This system allows for the discussion of the problem of the electronic structure of the heterojunction created by the two kinds of oxides. Comparison is made with the case of passive films on stainless steel. (C) 2003 Elsevier Ltd. All rights reserved.