Brillouin light scattering and ferromagnetic resonance in sputtered NiFe/Cu/NiFe thin films

The spin-wave spectra of Ni81Fe19(t)/Cu(25 Angstrom)/Ni81Fe19(t) with t = 200 and 300 Angstrom are investigated by means of Brillouin light scattering and ferromagnetic resonance. Samples grown on three different substrates, namely, MgO(100), MgO(110), and sapphire(0001), exhibit clear-cut volume and surface modes. Sharp linewidths are signatures of the excellent quality of the samples. Angle-dependent measurements reveal that, while the samples grown on MgO(100) and sapphire(0001) are nearly isotropic, a surprisingly large in-plane uniaxial anisotropy is a characteristic feature of the samples grown on MgO(110). Quantitative agreement between theoretical and experimental results is reported for a realistic set of the samples' parameters. (C) 1997 American Institute of Physics.