Magnetic anisotropy of epitaxial iron films on single-crystal MgO(001) AndAl2O3(11(2)over-bar0) substrates

The ferromagnetic resonance and magnetization of single-crystal thin (27-10 0 Angstrom films grown in the (110) direction are measured in the temperatu re range 20-400 K. The films are prepared by molecular-beam epitaxy on sing le-crystal sapphire Al2O3 (11 (2) over bar 0) substrates with a Nb(110)buff er layer. The angular dependence of the parameters of the ferromagnetic res onance spectrum is observed to have a 180 degrees character when the static magnetic field is rotated in the plane of the sample. It is established th at this angular dependence can be described on the assumption that the latt ice distortions are essentially trigonal. A comparative analysis of previou s data for Fe(001) films with the data for Fe(110) films shows that the sou rce of the corrections to the cubic anisotropy constant is the characterist ic distribution of the strains along the thickness of the film. (C) 1999 Am erican Institute of Physics. [S1063-7761(99)02102-2].