Effect of Dopants on the Soft Magnetic Properties and High Frequency Characteristics of FeCoBM (M = Ti, Nb, Hf, and Ta) Thin Films

Abstract

Effect of dopants on the soft magnetic properties and high frequency characteristics of FeCoBM thin films (M = Ti, Nb, Hf, and Ta) have been studied. For (Fe0.55Co0.45)(100-x)B(x) (x = 5-15) thin films, with the increase of B content, the resistivity was increased because B could decrease the crystallinity of the films. The (Fe0.55Co0.45)90B10 thin film showed the optimum properties, where 4piM(s) = 16.1 kG, H(ce) = 64.2 Oe, H(ch) = 13.5 Oe, H(k) = 310 Oe and p = 338 microomega-cm. To reduce the coercivity of the film, the elements M, including Ti, Nb, Hf, and Ta, were selected to substitute for B in the FeCoB films. It was found that (Fe0.55Co0.45)90B6Ti2Nb2 thin film after annealing at a temperature of 200 degrees C for 30 min showed the optimal properties, where 4piM(s) = 15.8 kG, H(ce) = 4.8 Oe, H(ch) = 3.6 Oe, H(k) = 224 Oe and p = 290 microomega-cm. The theoretically calculated ferromagnetic resonance frequency of the developed films can be higher than 5 GHz.

Electromagnetic Noise Suppression Characteristics of FeCoBM-Al₂O₃ Amorphous Soft Magnetic Films

“…FeCoB-Al 2 O 3 magnetic metal-insulator granular films show both good soft magnetic properties and high ρ , as their unique microstructure with dielectric amorphous phase were random embedded in nano-sized ferromagnetic particles [8]. Many metal elements, such as Ni, Nb, Zr, Hf, Mo, Ta, Ti etc, which can tailor the s M , coercive force ( Hc ), k H and ρ by affecting the microstructure and stress of the soft magnetic films, have been adopted into soft films [9][10][11][12]. In this paper, we studied electromagnetic noise suppression characteristics using amorphous FeCoBM-Al 2 O 3 (M=Nb, Zr, Hf, Mo, Ta, Ti) soft magnetic films.…”

Effect of Dopants on the Microwave Magnetic Characteristics of FeCoBM-Al₂O₃ Soft Magnetic Thin Films

“…To improve the most important characteristics (f r ,µ, eddy current loss) of the soft magnetic films , many works have been reported. Magnetic metal-insulator granular films (MIGF) such as FeCoB-N x O y (NxOy =SiO 2 ,Al 2 O 3 ,etc) show both good soft magnetic properties and high ρ, as their unique microstructure with dielectric amorphous phase were random embedded in nano-sized ferromagnetic particles [8][9][10][11].Many transition metal elements ,such as Nb, Zr, Hf, Mo ,Ta, Ti etc, which can tailor the M s , coercive force (H c ), H k and ρ by affecting the microstructure and stress of the soft magnetic films ,have been adopted into soft films [12][13][14][15][16][17][18][19][20][21][22][23].In this paper，We tried to adopt these elements into Fe 40 Co 40 B 20 -Al 2 O 3 films and the soft magnetic and microwave magnetic characteristics of these films were studied. The effects of annealing treatment on the magnetic properties of the films were also reported at the end of this paper.…”