Magnetic properties of oblique deposited (FeCoNiNbB)_x(SiO₂)_1-x granular films in a wide x range

Bangmin Zhang, Shihui Ge, Guowei Wang, Yuhua Xiao, Huaping Zuo and Li Zhang

Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University Lanzhou 730000, PRC

Corresponding author: gesh@lzu.edu.cn

Received: 20 October 2009
Accepted: 23 December 2009

Abstract

(Fe₅₇Co₂₄Ni₄Nb₂B₁₃)_x-(SiO₂)_1-x nano-granular thin films in a wide x range were fabricated by magnetron sputtering by oblique incidence. Excellent soft magnetic properties have been achieved with variable in-plane uniaxial magnetic anisotropy field H_k. For same oblique angle θ, with decreasing x, H_k increases first and reaches maximum at x = 0.88, then decreases; while the coercivity in the easy axis changes slightly and is less than 10 Oe and the resitivity ρ increases monotonously and exhibits a higher rate in x < 0.88. For films with θ = 15°, the sample x = 0.88 possesses a high FMR frequency f_r of 5.4 GHz and a large permeability of 40 up to 4.1 GHz. The sample x = 0.66 has both high resistivity and excellent soft magnetic properties, of which the coercivities in hard and easy axes are 3.1 and 2.4 Oe, respectively, H_k is 60 Oe, and ρ reaches 3.1 10³ μΩ cm. The magnetic spectrum μ = - shows that is more than 150 below 0.70 GHz and f_r reaches 1.70 GHz.