Bilinear exchange coupling in asymmetric Fe(110)/Cu/Fe(110) thin films studied by Brillouin Light Scattering -- Presentazione poster by R. Zivieri - Conferenza internazionale

The magnetic properties of bcc Fe(110) bilayers separated by fcc(111) Cu films of variable thickness in the range between 0 and 33 Å have been investigated by Brillouin light scattering (BLS). The two Fe films, 20 and 60 Å thick, are grown on the 7x7 reconstructed surface of a Si(111) substrate using the metal-metal epitaxy on silicon technique (MMES). [1] Low energy and Kikuchi electron diffraction analysis have revealed that the Fe films grow in the Kurdjumov-Sachs (KS) orientation on the underlying Fe layers pseudomorphic with Cu(111).[2] The experimental spin-wave frequency dependence on the applied magnetic field and on the incidence angle of light is simulated using a model which includes first-order intrinsic volume and interface anisotropies. BLS study has shown that, for Cu thickness between 0 and 33 Å, the exchange coupling is ferromagnetic, in agreement with our surface magneto-optic Kerr effect measurements, and that the biquadratic coupling is not negligible. The calculated BLS cross-sections agree very well with the measured spectra. [1] G. Gubbiotti, G. Carlotti, C. Minarini, S. Loreti, R. Gunnella, and M. De Crescenzi, Surf. Sci. 449, 218 (2000). [2] G. Gubbiotti, L. Albini, S. Tacchi, G. Carlotti, R. Gunnella, and M. De Crescenzi, Phys. Rev. B 60, 17150 (1999). -- Presentazione poster by R. Zivieri -Conferenza internazional