Anisotropy field distribution in Os-doped γ-Fe2O3thin films

Unusually-large, widely-distributed HkS are found on Os-doped γ-Fe2O3thin films. The average Hks are 10, 18 and more than 20 kOe for 0.9, 2.0 and 7.0 at.% Os-doped films, respectively. Large Wr(3-12×10⁵erg/cc ) remain even at a high magnetic field of 14 kOe, because of the Hkdistributions. Uniaxial anisotropy energy of 2×10⁵erg/cc, which is induced through magnetic-annealing, is because of the orientation of a small portion of the intrinsic anisotropy axes. Film characteristics indicate that lattice spacing of the γ-Fe2O3structure and Mössbauer parameters of Fe³⁺ions stay constant, irrespective of Os content. Os4f photo-electron binding energies agree with those for Os metal. An Os-deficient layer 200-400 Å in thickness at the top surface is detected.