Enhancement of ferromagnetic resonance in Al ₂ O ₃ -doped Co ₂ FeAl Heusler alloy film prepared by oblique sputtering

Abstract

Large and variable in-plane uniaxial magnetic anisotropy in a nanocrystalline (Co2FeAl)97.8(Al2O3)2.2 soft magnetic thin film is obtained by an oblique sputtering method without being induced by magnetic field or post annealing. The in-plane uniaxial magnetic anisotropy varies from 50 Oe to 180 Oe (1 Oe = 79.5775 Am−1) by adjusting the sample's position. As a result, the ferromagnetic resonance frequency of the film increases from 1.9 GHz to 3.75 GHz.

Ru thickness-dependent interlayer coupling and ultrahigh FMR frequency in FeCoB/Ru/FeCoB sandwich trilayers

“…[1] The IEC was widely used in magnetic devices, [2,3] such as magnetic recording devices, giant magnetoresistance effect, tunneling magnetoresistance effect, [4][5][6][7][8] etc. The materials currently used to study IEC are mainly composed of Fe, [9][10][11] Co, [12] FeCo, [13] NiFe, [14][15][16][17] and FeCo alloys, [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] separated by non-ferromagnetic materials, such as Cu, [14,35] Cr, [9,36] and Ru. [3,[15][16][17][18][24][25][26]37] For the FM/NM/FM structure, the coupling strength and type of IEC are mainly related to the material compositions and the thickness value of FM layer and NM layer.…”

“…This leads to enlarged OM and reduced AM resonance peaks. [27][28][29][30][31][32][33][34][35] The resonance mode can be easily identified from the relative intensities of the resonance peaks.…”

Angular control of multi-mode resonance frequencies in obliquely deposited CoZr thin films with rotatable stripe domains*

“…Obviously, the FMR frequency can only be tuned by regulating the H for a given material with a fixed M S . Different methods, including oblique deposition, [7][8][9] exchange bias, [10] exchange-coupled multilayer structures, [11][12][13][14][15][16][17][18] and depositing on pre-stressed substrates, [19,20] are often employed to adjust the f uni by changing the anisotropy of the magnetic films. But they are no longer effective once the sample works in devices, because these methods are applied during the sample preparation.…”

Improvement of high-frequency properties of Co2FeSi Heusler films by ultrathin Ru underlayer*

“…where γ, H K , and 4πM S refer to the gyromagnetic ratio, magnetic anisotropy field, and saturation magnetization of the SMFs, respectively. There are many approaches to improve the zero-field FMR frequency, such as oblique sputtering, [4,10] composition gradient sputtering (CGS), [11] magnetoelectric coupling, [5,12] exchange coupling, [13][14][15] interlayer exchange coupled optical mode resonance, [16,17] in-serting a underlayer, [18][19][20][21] etc. Among them, the oblique deposition technique is a simple and easily controllable method to tailor the magnetic anisotropies in magnetic films.…”