Microwave ferromagnetic properties of as-deposited Co ₂ FeSi Heusler alloy films prepared by oblique sputtering

Abstract

The Co2FeSi films are deposited on Si (100) substrates by an oblique sputtering method at ambient temperature. It is revealed that the microwave ferromagnetic properties of Co2FeSi films are sensitive to sample position and sputtering power. It is exciting that the as-deposited films without any magnetic annealing exhibit high in-plane uniaxial anisotropy fields in a range of 200 Oe–330 Oe (1 Oe = 79.5775 Am−1), and low coercivities in a range of 5 Oe–28 Oe. As a result, high self-biased ferromagnetic resonance frequency up to 4.75 GHz is achieved in as-deposited oblique sputtered films. These results indicate that Co2FeSi Heusler alloy films are promising in practical applications of RF/microwave devices.

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

“…[3] Recently, with the operation frequency reaching the microwave band, the research interests on the application of Heusler alloy films in microwave devices have been steadily increased. [4][5][6][7] We found that Heusler alloy has some unclear areas in the microwave field. Among Heusler alloys, Co 2 FeSi has fascinated the attention due to its interesting properties such as, high magnetic moment (6 µ B ) and high Curie temperature (1100 K) along with half metallic band structure.…”

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.…”

Anti-function solution of uniaxial anisotropic Stoner–Wohlfarth model

“…[1,4] At present, the SW model is not only widely used in magnetic recording media [5][6][7][8] and hard magnets [9,10] but also a basic model for describing the dynamic magnetic properties of soft magnetic materials under microwaves. [11][12][13][14][15] In addition, it provides an effective analysis model for magnetoelectric transport such as anisotropic magnetoresistance and anomalous Hall effect, [16][17][18] and spintronics research such as spin Hall magnetoresistance and spin Hall effect. [19,20] Determining the stable direction of magnetization under an applied magnetic field is the key to obtain the magnetizing curves and hysteresis loops, as well as understand the basic magnetic physical quantities.…”