Thickness dependence of magnetic anisotropy in uncovered and Cu-covered Fe∕GaAs(110) ultrathin films studied by in situ Brillouin light scattering

The thickness dependence of magnetic anisotropy in Fe∕GaAs(110) ultrathin films has been investigated by in situ Brillouin light scattering. A simultaneous best-fit analysis of the spin-wave frequency, measured as a function of (i) the intensity of the applied magnetic field, (ii) its direction in the film plane, and (iii) the incidence angle of light, enabled us to determine several magnetic parameters, including the film thickness, and both the in-plane and out-of-plane magnetic anisotropy constants. A marked evolution of the strength as well as of the symmetry of the in-plane magnetic anisotropy has been observed for increasing thickness. The effect of a nonmagnetic Cu capping layer on the magnetic properties of the Fe films has also been studied.