Browsing by Author "Eichner, S."

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    Electron-Spin Polarization at Single-Crystalline Cr and Ni Surfaces Determined with Electron-Capture Spectroscopy
    (American Physical Society, 1981) Rau, C.; Eichner, S.
    The spin polarization P of electrons at Cr and Ni surfaces is measured with electron-capture spectroscopy. With use of one-electron capture at magnetized Cr(100)-c(2×2) surfaces at 293 K (TN=310 K), P values up to -18% are found revealing ferromagnetic order at this surface. Utilizing two-electron capture at demagnetized Ni surfaces we find at 293 K (TC=631 K) |P|=94% for Ni(110), |P|=72% for Ni(100), |P|=47% for Ni(111), and |P|=14% for Ni(120). There is evidence that "local" ferromagnetic order at Ni surfaces exists even at 2TC.
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    Evidence for ferromagnetic order at gadolinium surfaces above the bulk Curie temperature
    (American Physical Society, 1986) Rau, C.; Eichner, S.
    The electron-spin polarization P at the topmost layer of atomically clean, magnetized gadolinium (Gd) surfaces is measured by using electron capture spectroscopy. P varies almost linearly with temperature between 160 K (P=-42%) and 315 K (P=0). It is found that the surface Curie temperature TCs is far above—lying near 310 K—the bulk Curie temperature TCb=292.5 K, indicating uniaxial anisotropic magnetic exchange interactions at the topmost surface layer of Gd.