Papers by Keyword: Ferromagnetic Resonance

Abstract: This paper delves into the magnetic properties of transition metal FeNi doping with heavy rare earth (RE) elements (including Gd and Nd) magnetic nanomultilayer films. Through experimental methods such as Vibrating Sample Magnetometer magnetic measurements and Ferromagnetic Resonance, the influence of rare earth element doping on the magnetic properties of FeNi alloy films is systematically analyzed. The experimental results reveal that the addition of rare earth elements significantly alters the saturation magnetization, coercivity, and magnetic anisotropy of FeNi alloys, with notable impacts on their ferromagnetic resonance behavior. This study not only provides crucial insights into the unique structures and magnetic mechanisms of rare earth-transition metal alloys but also offers theoretical support for the development of high-performance magnetic materials.

Abstract: Multilayer films exhibit high saturation magnetization, high permeability, and high cutoff frequency f_r, applying to magnetic inductors that satisfy both high frequency, miniaturization, and integration. In this work, we fabricate Fe/Ni₈₁Fe₁₉/Fe (t/100/t nm) multilayer films on Si (100) using electron beam evaporation, and investigate the Fe thickness dependence of surface morphology, saturation magnetization, coercivity, and ferromagnetic resonance f_r. The results demonstrate that Fe/Ni₈₁Fe₁₉/Fe (4/100/4 nm) multilayer film possess relatively high saturation magnetization (12.1 kGs), low coercivity (3.1 Oe), and high ferromagnetic resonance f_r (1.93 GHz).

Abstract: The structure, magnetic properties, ferromagnetic resonance and giant magnetoimpedance effect (GMI) were studied in Fe_xNi_100-x thin films and multilayered systems having compositions with small deviation from zero magnetostriction in order to find the best conditions for possible applications in the area of small pressure sensors. A comparative analysis of the effective magnetization and g-factor was carried out for the thin films of Fe_xNi_100-x (x = 19.8, 17.5, 15.0, 11.9) alloys. Comparison of the concentration dependences for static 4πM_s and dynamic 4πM_eff magnetization values allows to select a narrow interval of concentrations around Fe₁₅Ni₈₅ for the development of a microfluidic small pressure sensitive elements based on GMI effect. The maximum value of GMI ratio (ΔZ/Z) ratio shows linear dependence on the iron content in the Fe_xNi_100-x alloy for the concentration range under consideration.

Abstract: The phase composition, structural parameters, and basic magnetic characteristics of BaFe₁₂O₁₉ hexaferrites prepared by the mechanochemical synthesis with subsequent annealing at a temperature of 1000°С and 1100°С for 1 h are investigated. The influence of the annealing temperature on the properties of synthesized materials is analyzed. Values of the saturation magnetization and the anisotropy field are determined. It is established that annealing temperature in the interval 1000 - 1100 °C does not significantly affect on the phase composition and the size of nanoparticles. The value of the anisotropy field increases substantially with increasing temperature.

Abstract: The [Со_xNi_1–x]_N and [Со_xP_{1– x}]_N films with composition gradient were prepared by electroless deposition. The [(Co₄₀Fe₄₀B₂₀)_X(SiO₂)_100-X/α-Si:H]_N and [(Co₄₀Fe₄₀B₂₀)_X(SiO₂)_100-X/SiO₂]_N films were prepared by the ion-beam sputtering. It is found that the spin–wave resonance spectrum in these films is characterized by anomalous dependences of resonance fields of spin–wave modes H_r on the mode number: H_r(n) ~ n, H_r(n) ~ n^2/3.

Abstract: Excitation of hypersound elastic oscillations in the microwave on the magnetization reversal of the normal magnetized ferrite plate is studied in the paper. Characteristic times of the process of development of magnetic and elastic oscillations were revealed. Their relation to the parameters of the magnetic and elastic damping has been revealed.

Abstract: Static magnetic properties, ferromagnetic resonance (FMR) and glancing angle X-ray diffraction spectra (GAXRD) of (CoFeB)/(nonmagnetic interlayer) nanosystems have been studied for three kinds of interlayers: dielectric (SiO₂) and semiconductors (Si and SiC). Matter of discussion is the role of the interlayer material in forming of inner structure of magnetic layers and magnetization curve shape.

Abstract: The ferromagnetic and spin-wave resonance in the electroless deposited thin films of Fe-Ni alloy including alloy with invar content are studied. The dependences of resonance field on the number of mode extracted from spin-wave resonance spectra are deviated from the Kittel dispersion relation. The type and the size of magnetic heterogeneity are estimated in accordance with the spin-wave spectroscopy technique.

Abstract: The morphology and magnetic characterization results of electroless deposited CoP coating on the copper microgrid with the mesh size of 50 microns are presented and discussed. The deposited coating is found to be well uniform by the thickness. Magnetic anisotropy in the plane of the grid has been studied by the hysteresis loops and the FMR spectra and discussed with the modeling of the grid as the frame grid system of magnetic tubes.

Abstract: Multilayer nanogranular film structures (CoFeB)_m(SiO₂)_100-m have been investigated by ferromagnetic resonance (FMR). It is shown experimentally that for these films which magnetic phase content is below percolation threshold the variation of FMR fields is not related to the thickness of magnetic layers but can be explained by variation of the shape (elongation) of spheroidal magnetic granules. The observed results are explained within standard phenomenological FMR theory.