Study on the Room-temperature Oxidation of a Fe Thin Film on Pt(110)

Abstract

The chemical states of Fe-oxide films deposited on Pt(110) surfaces were investigated by using X-ray photoelectron spectroscopy. The films were prepared by exposing 4- or 6-monolayer (ML) Fe films pre-deposited on the substrates to oxygen. After a 300-Langmuir oxygen exposure at room temperature, the films were observed to be partially oxidized as a mixture of FeO and Fe(3)O(4) phases, and the relative amount of the Fe(3)O(4) phase was larger for the 6-ML Fe film than for the 4-ML film. Upon post-annealing, the oxides decomposed into Fe atoms and desorbing O(2) molecules, and the former interdifFused into the substrate at temperatures higher than 700 K.