Magnetic anisotropy of epitaxial iron films on single-crystal MgO(001) and \(Al_2 O_3 (11\bar 20)\) substrates

The ferromagnetic resonance and magnetization of single-crystal thin (27–100 A films grown in the (110) direction are measured in the temperature range 20–400 K. The films are prepared by molecular-beam epitaxy on single-crystal sapphire \(Al_2 O_3 (11\bar 20)\) substrates with a Nb(110)buffer layer. The angular dependence of the parameters of the ferromagnetic resonance spectrum is observed to have a 180° character when the static magnetic field is rotated in the plane of the sample. It is established that this angular dependence can be described on the assumption that the lattice distortions are essentially trigonal. A comparative analysis of previous data for Fe(001) films with the data for Fe(110) films shows that the source of the corrections to the cubic anisotropy constant is the characteristic distribution of the strains along the thickness of the film.