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We present a study of spin pumping efficiency and determine the spin mixing conductance and spin diffusion length in thin bilayer films based on 3d transition metal alloy Fe60Al40. Due to its magnetostructural phase transition, Fe60Al40 can be utilized as a ferromagnetic (FM) or paramagnetic (PM) material at the same temperature depending on its structural order; thus a thin Fe60Al40 film can act as a spin source or a spin sink when interfaced with a paramagnet or a ferromagnet, respectively. Ferromagnetic resonance measurements were performed in a frequency range of 5–35 GHz on bilayer films composed of FM–Fe60Al40/Pd and PM–Fe60Al40/Ni80Fe20 (permalloy). The increase in damping with the thickness of the paramagnetic layer was interpreted as a result of spin pumping into the paramagnet. We determine the spin mixing conductance g P d ↑↓ = (3.8 ± 0.5) × 10 18 m − 2 at the FM–Fe60Al40/Pd interface and the spin diffusion length λ P d = 9.1 ± 2.0 nm in Pd. For the PM–Fe60Al40/permalloy interface, we find a spin mixing conductance g F e A l ↑↓ = (2.1 ± 0.2) × 10 18 m − 2 and a spin diffusion length λ F e A l = 11.9 ± 0.2 nm for PM–Fe60Al40. The demonstrated bi-functionality of the Fe60Al40 alloy in spin pumping structures may be promising for spintronic applications. [ABSTRACT FROM AUTHOR]

An ultrahigh-vacuum-compatible setup for broad-band X-ray detected ferromagnetic resonance (XFMR) in longitudinal geometry is introduced which relies on a low-power, continuous-wave excitation of the ferromagnetic sample. A simultaneous detection of the conventional ferromagnetic resonance via measuring the reflected microwave power and the XFMR signal of the X-ray absorption is possible. First experiments on the Fe and Co L3-edges of a permalloy film covered with Co nanostripes as well as the Fe and Ni K-edges of a permalloy film are presented and discussed. Two different XFMR signals are found, one of which is independent of the photon energy and therefore does not provide element-selective information. The other much weaker signal is element-selective, and the dynamic magnetic properties could be detected for Fe and Co separately. The dependence of the latter XFMR signal on the photon helicity of the synchrotron light is found to be distinct from the usual x-ray magnetic circular dichroism effect. [ABSTRACT FROM AUTHOR]

We demonstrate how planar microresonators (PMRs) can be utilized to investigate the angular dependent magnetic resonance response of single magnetic nanostructures. In contrast to alternative detection schemes like electrical or optical detection, the PMR approach provides a classical means of investigating the high frequency dynamics of single magnetic entities, enabling the use of well-established analysis methods of ferromagnetic resonance (FMR) spectroscopy. To demonstrate the performance of the PMR-based FMR setup for angular dependent measurements, we investigate the microwave excited magnons in a single Co stripe of 5×1×0.02 μm³ and compare the results to micromagnetic simulations. The evolution of excited magnons under rotation of one individual stripe with respect to a static magnetic field is investigated. Besides quasi uniform excitations, we observe magneto-static as well as localized excitations. We find a strong influence of inhomogeneous dynamic and static demagnetizing fields for all modes. [ABSTRACT FROM AUTHOR]

We have proven that the growth of Co68Fe24Zr8 layers under external field yields a uniaxial anisotropy, defined by the direction of the field. No magnetic coupling is present between Co68Fe24Zr8 layers when separated by a 3 nm of Al70Zr30. The anisotropy axis can therefore be manipulated at will and the direction can be tailored, layer by layer in multilayers, by the choice of the direction of the applied field during growth. The g-factor (2.13) and the anisotropy constant, obtained from ferromagnetic resonance, support the existence of short-range order. The relation between the temperature dependences of magnetic anisotropy and magnetization are partially captured by Callen-Callen power law. [ABSTRACT FROM AUTHOR]

An amorphous Co68Fe24Zr8(3 nm)/Al70Zr30(3 nm)/Co68Fe24Zr8(3 nm) trilayer system has been investigated using in-plane and out-of-plane angular dependent ferromagnetic resonance at different frequencies. The in-plane magnetic anisotropy is uniaxial, retaining its value of (2.9 ± 0.1) × 103 J/m3 for each magnetic layer, whereas its direction was tailored independently in an arbitrary manner by applying an external magnetic field during the film deposition. The perpendicular anisotropy constant, supposed to reflect the interface quality, is nearly identical for both layers. Furthermore, the magnetic layers act independently upon each other due to the absence of interlayer coupling. [ABSTRACT FROM AUTHOR]

Nearly perfect single crystalline Fe core-shell nanocubes with (100) facets and 13.6 nm edge length were prepared by wet-chemical methods. While the core is metallic, the shell is composed of either Fe3O4 or γ-Fe2O3. The cubes were deposited onto GaAs substrates with monolayer coverage as proved by scanning electron microscopy. Oxygen and hydrogen plasmas were used to remove the ligand system and the oxide shell. Both types of samples were investigated by ferromagnetic resonance. While the g-factor (g=2.09) and crystalline anisotropy (K4=4.8×104 J/m3) of the pure iron cubes show up with bulk values, the saturation magnetization is reduced to (M(5K)=(1.2±0.12)×106 A/m) 70% of bulk value and the effective damping parameter (α=0.03) is increased by one order of magnitude with respect to bulk Fe. [ABSTRACT FROM AUTHOR]

Ferromagnetic resonance investigations of the magnetic anisotropy of Co/Cu(111) thin films reveals that the Co/Cu(111) system exhibits peculiarities associated with the structure and growth processes. The films are synthesized by molecular beam epitaxy (MBE) methods at ultra-high vacuum. The Co/Cu(111) films are grown on sapphire substrates using niobium as buffer layer. The films exhibit six-fold anisotropy.

The effect of Ni-ion implantation on the magnetic characteristics of permalloy thin films was investigated using spin-wave resonance analysis. The results showed that films with thicknesses ranging from 30-60 nm featured a uniform mode which shifted to higher resonance fields as the implantation dose increased. In the case of thicker samples, standing spin waves were only slightly affected by the implantation process. This behavior was attributed to the effects of surface anisotropy changes.

Spin wave modes in the surface and bulk of as-prepared FeNi multilayered thin films were investigated using spin wave resonance analysis. The results showed that in the perpendicular field configuration, nonpropagating surface spin wave modes and standing volume modes were present. The onset of these surface modes were associated with the surface anisotropy at the bottom and top layers of the structure.

The samples are prepared using standard lithography lift-off processes and constituted large arrays of at least 1000 stripes, such that enough material is available to perform conventional ferromagnetic-resonance (FMR) measurements. The overall anisotropy and resonance line behavior of the samples are found out by conventional FMR measurements.

An electrically conducting atomic force microscope tip was used as a sliding contact for conducting local magnetoresistance (MR) and ferromagnetic resonance (FMR) measurements on submicrometer Ni wires. The ratio of the radial anisotropy and the shape anisotropy were found to change for the constricted portion of the Ni wires.

Focuses on a study which investigated the standing spin-wave resonance in a multilayer structure composed of alternating layers of nickel and iron for the as-prepared sample and at different annealing temperatures. Experiment; Excitation of the surface mode in the sample; Impact of heating on behavior of the alloy.

Comments on an article about anisotropy studies of molecular-beam epitaxy-grown cobalt thin films by ferromagnetic resonance. Discussion on the appropriateness of an analysis on ferromagnetic resonance data from cobalt/copper single layers and superlattices; Importance of structural characterization for magnetic thin films.