Investigation of single crystal Fe films grown by MBE on GaAs substrates

Single crystal Fe films grown by molecular beam epitaxy (MBE) on (110) and (100) GaAs substrates have been investigated by means of ferromagnetic resonance (FMR), inelastic light scattering (BS) and SQUID magnetometry. The FMR linewidth at X-Band is typically 50 Oe. For all (110) films, growth-induced in-plane anisotropy with the easy axis // <110> is found, with strongly varying magnitude demonstrating a sensitive dependence on MBE growth parameters. The magnetization as determined by FMR strongly differs from the bulk Fe value. SQUID measurements show that this discrepancy cannot be explained in terms of a bulk out-of-plane anisotropy. BS from surface magnons is found to be in reasonable agreement with FMR data and offers, to that extent, a method to determine the thickness of very thin magnetic films.