Development and optimisation of FeCoHfN soft magnetic thin films with high-frequency characteristics

FeCoHfN thin films fabricated by co-sputtering with high resonance frequency

“…Nowadays, as the operating frequency in many devices reaches gigahertz, for instance the typical frequencies for Bluetooth technology are 2.4 and 5.8 GHz, the need for magnetic thin films with high resonance frequency is indispensable [2,3]. Among various materials, thin films based on FeCo alloy such as FeCoN [1], FeCoB [5][6][7], FeCo-SiO 2 [2,8], FeCo-Al 2 O 3 [9], FeCo-SiN [10], FeCo-HfO [11] and FeCo-HfN [12,13] have received much attention due to their relatively high saturation magnetization. In this paper, we report the investigation of magnetic dynamic properties of FeCoHfN thin films grown by co-sputtering of FeCo and Hf.…”

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].…”

Marked Enhancement of Roll-Off Frequency in FeCoN Synthetic Antiferromagnetic Films Deposited by Oblique Incidence

“…For the application of soft magnetic thin films with high frequency, controlling the magnitude of H k is essential. Compared to other methods for increasing the H k of FeCo thin films, such as depositing on prestressed substrates [7] or flexible substrates [8], micro strip patterning [12], introduces gradient of the Hf concentration [14,15] and using an organic semiconductors underlayer [16], our method is quite simple, more manageable and can get much more higher roll-off frequency. In this work, a feasible approach to conveniently controlling H k of FeCoN thin films by using oblique deposition and SAF structure can further improve their properties for the potential applications in the high frequency region.…”

“…But FeCo thin films with isotropic magnetic properties are not applicable for high frequency applications. Many efforts have been adopted to increase the H k of FeCo thin films, such as applying an induced magnetic field during film deposition [6], depositing on prestressed substrates [7] or flexible substrates [8], field annealing [9], stress inducing [10], oblique deposition [11], micro strip patterning [12], introducing gradient of the Hf concentration [13,14] and using an organic semiconductors underlayer [15]. However, it is still a big challenge getting a very large H k in soft magnetic films and enhancing their f r beyond 5 GHz.…”