Rj. Hicken et al., BRILLOUIN LIGHT-SCATTERING-STUDIES OF MAGNETIC-ANISOTROPY IN EPITAXIAL FE GAAS FILMS/, Journal of magnetism and magnetic materials, 145(3), 1995, pp. 278-292
Brillouin Light Scattering (BLS) measurements have been performed upon
epitaxial Fe/GaAs(100) and Fe/GaAs(($) over bar 110) films with parti
cular emphasis on Fe thicknesses less than 100 Angstrom. A continuum t
heory that is required to describe the experimental data is presented.
The values of the magnetic anisotropy fields measured by BLS agree we
ll with those obtained from detailed Magneto Optical Kerr Effect (MOKE
) studies. An in-plane uniaxial anisotropy is observed in addition to
the cubic anisotropy for both the (100) and (($) over bar 110) orienta
tions. For Fe/GaAs(100), both the cubic anisotropy field and the effec
tive demagnetizing field increase with film thickness while the uniaxi
al anisotropy field decreases with film thickness. For Fe/GaAs(($) ove
r bar 110) the uniaxial anisotropy field changes sign as the thickness
is increased. In light of these findings we discuss how the Fe/GaAs i
nterface may influence the values of the magnetization and anisotropy
constants in the Fe films.