Study of spin waves in ultrathin Fe/Cu(1 0 0) films by in situ Brillouin light scattering

The structural and magnetic properties of ultrathin Fe films, grown by e-beam evaporation on a Cu(1 0 0) single crystal, have been studied. The low-energy electron diffraction patterns account for a pseudomorphic growth of fcc-Fe(1 0 0) up to a thickness of a few nanometers, followed by a Pitsch transformation, consisting of bcc-Fe(1 1 0) domains. The magnetic properties of the films were investigated in situ by the combined use of surface magneto-optical Kerr effect and Brillouin light scattering. A ferromagnetic behaviour was detected for film thickness below about 1 nm and above 3 nm. A careful determination of the magnetic parameters and of the anisotropy constants of the ferromagnetic films was achieved by studying the dependence of the spin-wave frequency on the angle of incidence of light, on the intensity of the applied magnetic field and on its direction on the surface plane.