We probe the spin dynamics in a thin magnetic film at ferromagnetic resonance by nuclear resonant scattering of synchrotron radiation at the 14.4 keV resonance of 57 Fe. The precession of the magnetization leads to an apparent reduction of the magnetic hyperfine field acting at the 57 Fe nuclei. The spin dynamics is described in a stochastic relaxation model adapted to the ferromagnetic resonance theory by Smit and Beljers to model the decay of the excited nuclear state. From the fits of the measured data the shape of the precession cone of the spins is determined. Our results open a new perspective to determine magnetization dynamics in layered structures with very high depth resolution by employing ultrathin isotopic probe layers.

We present lateral spin-valve measurements where spin pumping serves as the spin current injection mechanism. The first electrode is excited at ferromagnetic resonance and the voltage drop between the interconnecting nonmagnetic channel and the second electrode with static magnetization is detected. We find a voltage difference of 10 nV between parallel and antiparallel magnetization alignment of the electrodes caused by spin-dependent differences in the chemical potential. The experimental value is in good agreement with a theoretical estimation of 12 nV. Our interpretation of the voltage signals is supported by simultaneous broadband-ferromagnetic resonance measurements.

We investigate the magnetization dynamics in pairs of mesoscopic permalloy (Ni80Fe20) rectangles by means of broadband-ferromagnetic resonance measurements and micromagnetic simulations. Each pair consists of two rectangles that differ in their geometry. The local effective field at each element is significantly affected by the stray field of its neighbor for small center-to-center distances between the rectangles. In antiparallel magnetization alignment, this dynamic dipolar coupling becomes prominent and anticrossing between ferromagnetic resonance modes and higher-order spin-wave modes is observed. Combination of the experimental and the simulational findings provides a comprehensive understanding of dynamically coupled rectangles.

We study spin-wave spectra of mesoscopic ferromagnetic Sierpinski carpets by means of broadbandferromagnetic resonance measurements and micromagnetic simulations. Sierpinski carpets are self-similar fractals with noninteger Hausdorff dimension that are constructed via a deterministic iteration process. The number of quantized spin-wave modes in the spectra increases with the iteration level of the carpets and the frequency splitting resembles bandpass characteristics known from fractal antennas. We find that the splitting is sensitive to the fractal dimension as well as to the relative alignment of the magnetic field and the sides of the fractals. Micromagnetic simulations provide the localization of individual spin-wave modes determined by the confinement and the inhomogeneity of the internal field.