AVS 45th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Thursday Sessions
       Session MI-ThA

Paper MI-ThA10
Magnetic Properties of Ultrathin Fe/Gd and Gd Thin Films

Thursday, November 5, 1998, 5:00 pm, Room 324/325

Session: Structure & Magnetism of Surfaces & Interfaces
Presenter: C.S. Arnold, National Institute of Standards and Technology
Authors: C.S. Arnold, National Institute of Standards and Technology
D.P. Pappas, National Institute of Standards and Technology
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Ultrathin films of magnetic transition metals are known to grow amorphously on rare-earth substrates. Magnetically, these films exhibit a strong perpendicular anisotropy and antiferromagnetic coupling of the transition metal to the rare earth atoms at the interface. Fe films 1- 4 monolayers thick grown on Gd substrates conform to this behavior, but also exhibit a reorientation phase transition (RPT) with temperature. This RPT is unlike those of ultrathin films on non-magnetic substrates because it is driven by the loss of magnetic order in the substrate as the bulk Gd Curie temperature is approached. Spin-polarized secondary electron polarimetry and SMOKE susceptibility measurements are employed to study the surface, bulk and interfacial magnetization as a function of temperature and Fe thickness. A partial thickness-temperature phase diagram is constructed. A second focus of the work is a comparison of surface and bulk magnetization vs. temperature in thin Gd films. The existence of a magnetic surface state is well established by spin-polarized spectroscopies, but direct comparisons of surface and bulk macroscopic magnetizations are rare in the literature. An earlier experiment using MOKE and electron spin-polarimetry to measure M(T) for the bulk and surface respectively is repeated.