Hysteretic properties of epitaxial Fe/GaAs(100) ultrathin films under external uniaxial strain

We report an experimental and theoretical study of the influence of uniaxial strain on the magnetic properties of Fe/GaAs(100) ultrathin film systems. In-plane tensile strains have been applied along different directions relative to the intrinsic uniaxial magnetic anisotropy axes of the Fe/GaAs(100) films, and the M-H loops were measured. In an attempt to interpret the observed behavior, a phenomenological energy model is considered, which incorporates both intrinsic and strain-induced uniaxial anisotropy terms. Theoretical magnetization reversal loops were obtained from the model, assuming that the magnetoelastic coefficients of the thin films are same as the bulk bcc Fe. The model qualitatively predicted the magnetization loops for all the experimental data, assuming a positive uniaxial anisotropy constant. (C) 2004 American Institute of Physics.