Magnetic anisotropies in Fe(110) films on W(110) (abstract)

Magnetic anisotropies in epitaxial Fe(110) films on W(110) were analyzed using torsion oscillation magnetometry (TOM) in situ in UHV. Films with clean surfaces and films coated by Cu, Ag, and Au were analyzed. Out-of-plane anisotropies were determined by standard TOM methods, in-plane anisotropies from hard-axis magnetization loops. All anisotropies showing a clear linear dependence on reciprocal film thickness, a straightforward separation of volume- and surface-type anisotropies could be performed. Volume anisotropies can be explained as a superposition of standard fourth-order magnetocrystalline and of strain anisotropies, caused by residual strain of a Fe coincidence lattice on W. Surface anisotropies, both in-plane and out-of-plane, are connected by Néel’s model with bulk magnetoelastic constants, to a surprisingly good approximation.