The initial stages of oxidation of thin iron films as studied by ferromagnetic resonance

Abstract

A series of polycrystalline iron films (1 < t < 100 nm) was prepared and examined under ultrahigh vacuum conditions. The effect of oxygen on the ferromagnetic resonance response was investigated, and a thickness-dependent, transient increase in the perpendicular mode resonance field was attributed to the formation of Fe m+ cations in a reconstructed surface layer. A subsequent decrease in the resonance field was consistent with the loss of ∼1.5 nm of ferromagnetic iron at large oxygen exposures. Information on the structure of the films was obtained from transmission electron microscopy of ultrahigh vacuum deposited films coated in situ with silicon monoxide.