arXiv subjects

M. Kostylev

Publications and source records attributed to M. Kostylev.

22 records · Page 2Linked to original sources

arXiv2009

Microwave screening by conduction currents in thin magnetic films: application in stripline broadband FMR

Ferromagnetic resonance in conducting magnetic bilayers was studied using microstrip transducers. It was found that excitation or suppression of standing spin waves could be achieved through enhanced inhomogeneity of eddy currents in the bilayer caused by finite thickness. This effect is observable in films with thicknesses below the magnetic skin depth and can be used to study standing spin wave modes in heterostructures.

cond-mat.mtrl-sci↗

arXiv2008

Strong asymmetry of microwave absorption by bi-layer conducting ferromagnetic films in the microstrip-line based broadband ferromagnetic resonance

Peculiarities of ferromagnetic resonance response of conducting magnetic bi-layer films of nanometric thicknesses excited by microstrip microwave transducers have been studied theoretically. Strong asymmetry of the response has been found. Depending on the order of layers with respect to the transducer either the first higher-order standing spin wave mode, or the fundamental mode shows the largest response. Film conductivity and lowered symmetry of microwave fields of such transducers are responsible for this behavior. Amplitude of which mode is larger also depends on the driving frequency. This effect is explained as shielding of the asymmetric transducer field by eddy currents in the films. This shielding remains very efficient for films with thicknesses well below the microwave skin depth. This effect may be useful for studying buried magnetic interfaces and should be accounted for in future development of broadband inductive ferromagnetic resonance methods.

cond-mat.mtrl-sci↗

arXiv2008

Self-organized plane arrays of metallic magnetic elements

We studied the dynamic magnetic properties of plane periodical arrays of circular permalloy nano-dots fabricated using a self-organized mask formed by polysterene nanospheres on the surface of a Permalloy film. Conventional (microwave cavity) and broadband coplanar-line ferromagnetic resonance setups were used for the measurements. We found several well resolved resonance peaks. This result shows that the self-organized mask fabrication technique is able to produce high-quality samples with small dispersion of geometrical and magnetic parameters.

cond-mat.mtrl-sci↗

arXiv2007

Formation of quasi-solitons in transverse confined ferromagnetic film media

The formation of quasi-2D spin-wave waveforms in longitudinally magnetized stripes of ferrimagnetic film was observed by using time- and space-resolved Brillouin light scattering technique. In the linear regime it was found that the confinement decreases the amplitude of dynamic magnetization near the lateral stripe edges. Thus, the so-called effective dipolar pinning of dynamic magnetization takes place at the edges. In the nonlinear regime a new stable spin wave packet propagating along a waveguide structure, for which both transversal instability and interaction with the side walls of the waveguide are important was observed. The experiments and a numerical simulation of the pulse evolution show that the shape of the formed waveforms and their behavior are strongly influenced by the confinement.

nlin.PS↗