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The ferromagnetic resonance (FMR) linewidth ΔH is a parameter used to characterize ultrathin film quality. The frequency-independent part, ΔH(0), reflects the contribution of magnetic inhomogeneities. The linear part is caused by the intrinsic Gilbert damping mechanism. Recently we have found that the lattice reconstructions of substrate templates strongly affects the FMR linewidth. bcc Fe(001) films (∼10 ML) were grown on unreconstructed fcc Ag(001), bcc Cu(001), and on surface reconstructed bcc Cu(001) templates. Fe layers grown on unreconstructed Cu templates exhibited an isotropic FMR linewidth. Fe layers grown on reconstructed Cu templates, on the contrary, showed an anisotropic behavior in both the zero-frequency FMR linewidth and the intrinsic damping parameter. Other magnetic parameters such as uniaxial and 4-fold anisotropies are also discussed.

Articles you may be interested inPrecise determination of the spectroscopic g-factor by use of broadband ferromagnetic resonance spectroscopya)

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A new phase of Pd with an expanded lattice (5%) was grown on Fe(001). Ultrathin Fe/Pd and Pd/Fe bilayers and Fe/Pd/Fe trilayers were studied using ferromagnetic resonance and Brillouin scattering. Pd interlayers always couple the Fe layers ferromagnetically. For thicknesses up to four monolayers the Pd is ferromagnetic, in agreement with theory. One additional atomic layer of Pd destroys the ferromagnetism, but the Pd still exhibits a fluctuating magnetic moment partly polarized by the exchange field from adjacent Fe layers. The magnetic moments in the interfaces were determined from the ferromagneticresonance absorption intensities.PACS numbers: 75.50.Bb, 75.70.AkThe magnetic properties of palladium metal have galvanized both theorists and experimentalists. The valence band of Pd metal is similar to that of Ni which has the same lattice structure and the same number of valence electrons. Since Ni is ferromagnetic, numerous attempts have been made to convert metallic Pd to the ferromagnetic state. The free Pd atom with a 4d ]0 5s° configuration is nonmagnetic. However, in metallic Pd the Ad band is not entirely filled. The intra-atomic Coulomb interactions between Ad electrons are responsible for an anomalously large Pauli susceptibility. The repulsive intra-atomic Coulomb interaction is so strong that the d band is near the threshold of becoming ferromagnetic. The role of intra-atomic Coulomb interactions can be enhanced by increasing the atomic volume. Brodsky's group studied ^(001)/Pd(001 )A4(001) {A = Ag,Au) sandwiches and tried to trigger the ferromagnetic state in Pd by stretching the Pd lattice by about 2.4% using ,4(001) templates. * They found an enhancement of several thousand times in the Pauli susceptibility, but the ferromagnetic state in the Pd layers was never achieved. Recently, interest in Pd has increased strongly. First, the Philips group used Pd interlayers in Co/Pd superlattices which showed a large perpendicular anisotropy in which the saturation magnetization was oriented perpendicular to the sample surface. 2 Second, several theoretical papers have predicted interesting magnetic properties for Pd structures which can, in principle, be grown by molecular-beam epitaxy (MBE). Nonrelativistic calculations by Moruzzi and Marcus 3 and by Chen, Brener, and Callaway 4 predicted an onset of ferromagnetism in fee Pd for a 5% increase in the lattice constant. Recently Blugel et al. 5 studied a Pd(00l) bulk substrate covered by 3rf-transition-metal monolayers. They showed that the Pd substrate enhances the magnetic moment in Fe by l//# and that the Fe overlayer induces a noticeable magnetic moment in the two nearest Pd layers (032JIB and 0Alji B in the first and second layer, respectively). Bergmann and Liu and Bader 7 saw strong evidence that a submonolayer of Fe induced a magnetic moment in a bulk Pd substrate. SQUID and Brillouin-light-scattering (BLS) measurements by Hillebrands, Baumgart, and Guntherodt 8 showed an induced magnetic moment in the Pd layers of Fe(011)/Pd(l 11) superlattices. Howeve...