AVS 46th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Monday Sessions
       Session MI-MoM

Paper MI-MoM8
MBE Growth and Characterization of bcc Fe@sub X@Co@sub 1-X@/GaAs(001) Heterostructures

Monday, October 25, 1999, 10:40 am, Room 618/619

Session: New Magnetic Materials
Presenter: L.C. Chen, University of Minnesota
Authors: L.C. Chen, University of Minnesota
B.D. Schultz, University of Minnesota
J.Q. Xie, University of Minnesota
C.J. Palmstrom, University of Minnesota
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We have successfully grown bcc Fe@sub X@Co@sub 1-X@ on GaAs(001) at 175°C by Molecular Beam Epitaxy. In-situ reflection high energy diffraction indicates a two dimensional growth mode of epitaxial bcc Fe@sub X@Co@sub 1-X@ on GaAs(001). A 40Å thick Al protective layer was deposited in-situ at a substrate temperature <0°C prior to removal from the MBE system. Ex-situ atom force microscopy studies show atomic steps indicative of a step-flow growth mode. X-ray diffraction data reveal an epitaxial orientation of bcc Fe@sub X@Co@sub 1-X@(001)||GaAs(001). A Rutherford backscattering spectrometry channeling minimum yield of @chi@=11% suggests good crystalline quality epitaxial bcc Fe@sub X@Co@sub 1-X@. Vibrating sample magnetometry measurements revealed in-plane magnetization and square hysteresis loops. In order to minimize interfacial reactions and diffusion during the Fe@sub X@Co@sub 1-X@ growth, we investigated the use of an epitaxial Sc@sub X@Er@sub 1-X@As diffusion barrier interlayer. Sc@sub X@Er@sub 1-X@As is thermodynamically stable on, and is lattice matched to, GaAs. Reflection high energy diffraction indicates a two-dimensional growth mode of epitaxial single crystal Fe@sub X@Co@sub 1-X@ film growth on the Sc@sub X@Er@sub 1-X@As surface at both 175°C and 470°C. Both ex-situ Rutherford backscattering spectrometry and in-situ Auger electron spectroscopy did not detect arsenic in Fe@sub X@Co@sub 1-X@ films. The effect of Sc@sub X@Er@sub 1-X@As thickness and Fe@sub X@Co@sub 1-X@ growth temperature on the growth mode and magnetic properties will be discussed. Further studies of interfacial transportation properties will also be reported.