Optimization of high frequency characteristics in Co-Ta thin films

Abstract

Magnetic properties and high frequency characteristics of binary Co100−xTax (x = 0–24) thin films, prepared by using the oblique sputtering method under an external magnetic field of 1200 Oe have been studied. All the Co100−xTax films are easy to form amorphous phase, and thus exhibit strong in-plane uniaxial magnetic anisotropy, high resistivity, and low coercivity. With increasing x, the saturation magnetization (4πMs) and coercivity along the easy and hard axes (Hce and Hch) are decreased, while the magnetic anisotropy field (Hk) reaches the maximum value of 578 Oe for the films with the composition to become fully amorphous phase. Due to large Hk, high ferromagnetic-resonance frequency (fFMR) of 4.7–6.6 GHz is obtained for Co100−xTax (x = 11–24) films. The optimal magnetic properties of 4πMs = 10.9 kG, Hce = 6.2 Oe, Hch = 6.0 Oe, Hk = 507 Oe, and high resonance characteristics of fFMR = 6.4 GHz, respectively, are reached for Co84Ta16 films. Finally, high fFMR of 5.4–7.2 GHz and Hk of 434–617 Oe can be tuned by the modification of the sputtering parameters. This result reflects the benefit of Co100−xTax (x = 11–22) films for above 5 GHz applications.

Soft Magnetic Properties of High-Entropy Fe-Co-Ni-Cr-Al-Si Thin Films

“…In brief, magnetic thin films are considered as the potential candidate for thin-film inductors with an aim to improve their M s , H k , ρ, and also compatibility with semiconductor manufacturing processes. Therefore, tremendous efforts have been devoted to developing better magnetic thin films over past decades [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].…”

Multidirectional available high-frequency response with zero-field resonance above 8 GHz in epitaxial α-Fe(001) films

“…agnetic materials with a high permeability have been extensively utilized in many high-frequency applications such as microwave noise filters, thinfilm inductors and so on. [1][2][3][4][5][6][7][8] As the operating frequency in many modern devices reaches the gigahertz range, various magnetic thin films with a high resonance frequency f r (above 6 GHz) [6][7][8][9][10][11] have been developed by employing their in-plane uniaxial magnetic anisotropy 10) or unidirectional anisotropy. 11) However, optimal high-frequency characteristics can only be approached under the condition that the microwave magnetic field is perpendicular to the unique easy axis for such kind of magnetic anisotropy.…”