Ultrahigh-frequency ferromagnetic properties of FeCoHf films deposited by gradient sputtering

Abstract

Nanocrystalline FeCoHf films with Hf composition gradient were prepared by gradient sputtering method at room temperature. A uniaxial magnetic anisotropy with high anisotropy field Hk up to 547Oe was achieved after magnetic annealing with external field along the gradient direction. Ultrahigh ferromagnetic resonance frequency over 7GHz was obtained in magnetic annealed gradient sputtered films. The origin of ultrahigh ferromagnetic properties in gradient sputtered films is discussed.

Magnetic characteristics of a high-layer-number NiFe/FeMn multilayer

“…1,2 Microwave frequency response is important for a number of device applications and has been explored within the context of exchange bias. [3][4][5][6][7] The exchange bias of FM layers within a composite FM/AFM multilayer can be controlled by the FM layer thickness. Tailoring these thicknesses within a multilayer can give rise to a range in the absorption frequencies and has applications in broadband microwave shielding.…”

Microwave Frequency Performance and High Magnetic Anisotropy of Nanocrystalline Fe<SUB>70</SUB>Co<SUB>30</SUB>-B Films Prepared by Composition Gradient Sputtering

“…As described in our previous work, [19][20][21] the CGS method gives rise to a gradient distribution of doping elements along the radial direction, leading to a similar stress dis-tribution. This residual stress results in a high UMA.…”

“…[15][16][17][18] In our previous work, an alternative method, Composition Gradient Sputtering (CGS), was proposed to prepare high UMA soft magnetic films, which dramatically increases H K up to 547 Oe due to the composition gra-dient induced uniaxial residual stress, and therefore good highfrequency characteristics were obtained. [19][20][21][22] target will have a gradient which increases gradually from inner (I) to outer (O) along the radial orientation (R). [19][20][21] Si (100) substrates with the dimension of 20 mm × 75 mm were pasted on the sample turntable ( Fig.…”

“…[19][20][21][22] target will have a gradient which increases gradually from inner (I) to outer (O) along the radial orientation (R). [19][20][21] Si (100) substrates with the dimension of 20 mm × 75 mm were pasted on the sample turntable ( Fig. 1(a)) with the length direction of the substrate along the radial direction (R) of the turntable.…”

Self-biased microwave ferromagnetic performance of patterned Ni80Fe20 thin films

“…4 Therefore, metal SMFs with endogenous magnetic anisotropy draw an increasing attention because, on the one hand, the endogenous magnetic anisotropy results in a good microwave magnetic properties in zero-bias magnetic field, on the other hand, metal films have good compatibility with MMIC process. 5,6 Various methods are developed to obtain large endogenous magnetic anisotropy field H K , such as in-situ magnetic field deposition, 7-9 post magnetic field annealing, 10,11 oblique sputtering, 12-14 composition gradient sputtering, 15,16 Interface coupling, 17,18 magnetoelectric coupling, 19,20 Stress induced, 21 and pattern processing, 22,23 etc.…”