Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5364930 | Applied Surface Science | 2008 | 7 Pages |
Abstract
Initial oxidation of iron and manganese mono-silicides (FeSi and MnSi) surfaces was studied by X-ray photoelectron spectroscopy (XPS). Clean surfaces of these silicides were prepared by fracturing in an ultra high vacuum, and then the fractured surfaces were oxidized by exposing to high-purity oxygen at pressures up to 1.3Â Pa. For the clean FeSi surface, positive chemical shifts of the Fe 2p3/2 and Si 2p peaks from elemental Fe and Si were 0.5Â eV and 0.1Â eV, respectively. For the clean MnSi surface, a negative chemical shift of the Si 2p peak from elemental Si was 0.1Â eV. Iron on the FeSi surface was oxidized at an oxygen pressure of 1.3Â Pa, whereas the silicon was oxidized under the pressure of 1.3Â ÃÂ 10â6Â Pa, indicating that oxidation of silicon occurred prior to that of iron. Manganese and silicon on the MnSi were simultaneously oxidized in the range from 1.3Â ÃÂ 10â6Â Pa to 1.3Â ÃÂ 10â3Â Pa; however, over the pressure of 1.3Â Pa, the oxidation of manganese occurs prior to that of silicon. These oxidation behaviors at low oxygen pressures were similar to those of the FeSi and MnSi fractured in air.
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Authors
Naofumi Ohtsu, Masaoki Oku, Akiko Nomura, Takamasa Sugawara, Toetsu Shishido, Kazuaki Wagatsuma,