Ferromagnetism and a temperature-driven reorientation transition in thin itinerant-electron films

Article

关键词: MAGNETIC SURFACE ANISOTROPY;    ULTRATHIN FE FILMS;    MAGNETOCRYSTALLINE ANISOTROPY;    INPLANE MAGNETIZATION;    HUBBARD-MODEL;    DIRECTION;    THICKNESS;    MOMENT;    DEPENDENCE;    MONOLAYERS;   

DOI  :  10.1103/PhysRevB.58.831

来源: SCIE

【 摘 要 】

The temperature-driven reorientation transition which, up to now; has been studied by use of Heisenberg-type models only, is investigated within an itinerant-electron model. We consider the Hubbard model for a thin fcc(100)film together with the dipole interaction and a layer-dependent anisotropy field. The isotropic part of the model is treated by use of a generalization of the spectral:density approach to the film geometry. The magnetic properties of the film are investigated as a function of temperature and film thickness and are analyzed in detail with help of the spin- and layer-dependent quasiparticle density of states. By calculating the temperature dependence of the second-order anisotropy constants we find that both types of reorientation transitions, from out-of-plane to in-plane (Fe-type) and from in-plane to out-of-plane (''Ni-type) magnetization are possible within our model. In the latter case the inclusion of a positive volume anisotropy is vital. The reorientation transition is mediated by a strong reduction of the surface magnetization with respect to the inner layers as a function of temperature and is found to depend significantly on the total band occupation. [S0163-1829(98)03926-5].

【 授权许可】

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