High-frequency permeability spectra of FeCoSiN/Al2O3 laminated films: Tuning of damping by magnetic couplings dependent on the thickness of each ferromagnetic layer

Abstract

Magnetization reversal and magnetoresistance behavior of perpendicularly magnetized [Co/Pd]4/Au/[Co/Pd]2 nanowires J. Appl. Phys. 112, 073902 (2012) Electric-field control of CoFeB/IrMn exchange bias system J. Appl. Phys. 112, 064120 (2012) Critical effect of spin-dependent transport in a tunnel barrier on enhanced Hanle-type signals observed in threeterminal geometry Appl. Phys. Lett. 101, 132411 (2012) Giant tunneling magnetoresistance in epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions by halfmetallicity of Co2MnSi and coherent tunneling Appl. Phys. Lett. 101, 132418 (2012) Interface mediated ferromagnetism in bulk CuO/Cu2O composites Appl.In this work, we investigate the high-frequency permeability spectra of as-sputtered FeCoSiN/ Al 2 O 3 laminated films, and discuss their dependence on the thickness of each FeCoSiN layer, based on the phenomenological Landau-Lifshitz-Gilbert equation. The damping factor and coercivity show their minima with lamination, deviating from the expectation based on the grain size confinement effect. Such dependences on the layer thickness indicate the influence of magnetic coupling. The decreases in the damping factor and the coercivities with lamination can be partially attributed to the decrease in the magnetostatic coupling induced by ripple structures. The enhanced damping and enlarged coercivity values obtained with further lamination are ascribed to the enhanced Néel couplings. The dependences show that the lamination can be effective in tuning the magnetization dynamics by changing the magnetic couplings.

[Fe80Ni20–O/SiO2]n Multilayer thin films for applications in GHz range

“…A feasible way to avoid the deteriorations of properties is introducing the nonmagnetic and insulated phases as the interlayer for laminating the films into multilayer thin films [15,16]. The inserted nonmagnetic insulated phases not only promote the r to restrain eddy current loss at high frequency but also protect the performance of each ferromagnetic layer without extrinsic influences to achieve the larger thickness for practical application.…”

Influence of magnetic layer thickness on [Fe 80 Ni 20 —O/SiO 2 ] n multilayer thin films

“…Usually Fe-based alloys with high M s are used for providing magnetic moments, and different insulating phases are widely studied to improve the values of ρ and H k in order to obtain good magnetic properties when operating in GHz range. [10][11][12] In our previous work, we chose Fe 80 Ni 20 -based alloy as the magnetic layer and systematically investigated the effects of different insulating phases used as the interlayer on the magnetic properties of multilayer thin films, and achieved high-frequency soft magnetic multilayer thin films with excellent properties. [13] In this paper, the [Fe 80 Ni 20 -O/SiO 2 ] n multilayer thin films are prepared with the SiO 2 interlayer thickness fixed at 3 nm.…”

The Structure and Magnetic Properties of NiZn-Ferrite Films Deposited by Magnetron Sputtering at Room Temperature

“…A solution to solve this problem is to construct a composite multilayer film consisting of ferromagnetic metal or alloy nanocrystalline layers which have high saturation magnetization and magnetic ferrite layers which have high resistivity. In this case, the introduction of the magnetic ferrite layer can increase not only resistivity but also saturation magnetization of the whole multilayer film compared to the introduction of nonmagnetic insulator layer such as Al 2 O 3 and SiO 2 [9,10]. NiZn-ferrite thin films with spinel structure have attracted particular interest because they exhibit the comprehensive advantages such as chemical stability, large electrical resistivity, relative high saturation magnetization, and low eddy current losses [11,12].…”