Epitaxial Fe72Co28(112) Films Grown on MgO(110) Substrates

Abstract
The (112) epitaxial Fe72Co28films with bct symmetry (c/a≤1) were grown on MgO(110) substrates by ion beam sputtering. These films exhibited a low coercive force of 150 A/m in the hard magnetization axis with large saturation magnetization of 2.4 T although the body-centered Fe-Co system has large magnetostriction. These epitaxial films had a uniaxial anisotropy in (112) plane with [111̄] easy axis, and the energy of this in-plane anisotropy depended on the acceleration voltage of the sputtering ion beam gun. The in-plane magnetic anisotropy dependence against the acceleration voltage was discussed in terms of the bct lattice strain effect based on the pseudo-dipolar interaction model.