Co-Fe metal/native-oxide multilayers: a new direction in soft magnetic thin film

2020-03-14 17:41:46

magnetic Soft Metal Native oxide

责任者: Beach, G.S.D.;Berkowitz, A.E. 单位: Dept. of Phys., Texas Univ., Austin, TX, USA 来源出处: IEEE Transactions on Magnetics(IEEE Trans. Magn. (USA)),2005/06/,41(6):2053-63 摘要: CoxFe100-x metal/native-oxide multilayer (MNOM) films exhibit soft magnetic properties, large magnetization, high resistivity, and a potential operating bandwidth of several gigahertz. These attractive characteristics are facilitated by ultrathin magnetic native oxide layers introduced to provide a high-resistivity barrier between nanocrystalline metal layers while preserving interlayer coupling and contributing to the net moment. This paper addresses several important features of the MNOM system from a microscopic perspective. The uniaxial anisotropy of MNOM thin films is discussed in detail and exchange averaging is invoked to account for its vanishingly small effective dispersion. The role of the native oxide in establishing interlayer exchange coupling is demonstrated, and a detailed account of the nature of the oxide is presented. In the Fe MNOM system, the oxide is shown to have a volume-averaged magnetization of 732(35) emu/cm3, with a temperature dependence comparable to that of metallic Fe. The magnetism of this largely interfacial oxide is supported by the metal and collapses in the absence of the metal. The oxide retains a large net moment for Co fractions up to at least x=50, but oxide magnetism is lost at high Co fractions, coinciding with the loss of soft magnetic properties 关键词: cobalt alloys;iron alloys;magnetic anisotropy;magnetic multilayers;magnetic permeability;magnetic thin films;soft magnetic materials;Co-Fe metal-native-oxide multilayers;soft magnetic thin film design;microscopic characteristics;CoxFe100-x metal-native-oxide multilayer;uniaxial anisotropy;MNOM thin films;interlayer exchange coupling;volume-averaged magnetization;soft magnetic properties;magnetic multilayers;magnetodynamics;permeability;soft magnetic materials;magnetic recording;magnetic shielding;CoFe