MAGNETIC-PROPERTIES OF BCC CO FILMS

The magnetic properties of epitaxial bcc Co films of thickness 10-100 angstrom have been investigated using the surface magneto-optic Kerr effect (SMOKE), polarized neutron reflection (PNR), and nuclear magnetic resonance (NMR). The in-plane coercivity is found to vary strongly with thickness and a large magnetocrystalline anisotropy develops in-plane at 60 angstrom which is maintained in thicker films. PNR measurements on a Au-coated 100-angstrom bcc Co film at 300 K are consistent with a layer averaged magnetic moment per atom of 1.4-mu-B and a magnetization profile within 50 angstrom of the GaAs interface. NMR measurements on a 75-angstrom bcc Co film at 4.2 K yield the center frequency consistent with a moment per atom of 1.4-mu-B.