Low energy ion bombardment and surface spin pinning in yttrium iron garnet films

Surface spin pinning and physical and chemical changes on the surface of yttrium iron garnet crystalline films were investigated. The magnetic properties of these films as determined by magnetostatic surface waves and ferromagnetic resonance measurements were studied as functions of Ar ion energy E/sub i/=200-1000 eV and ion dose D/sub i/=10/sup 14/-10/sup 18/ ions/cm/sup 2/. The surface spin pinning appears in a mildly damaged, non-stoichiometric layer with oxygen depletion. An alternative mechanism for the surface spin pinning effect based on an anisotropy associated with the oxygen vacancies and iron ion valence changes is proposed.<
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