Magnetic properties, adhesive characteristics, and optical properties of Co₄₀Fe₄₀W₂₀ films

ABSTRACT

X-ray diffraction patterns demonstrated a significant nanocrystalline body-centred cubic CoFe (110) structure when the thickness was between 60 and 90 nm, and displayed an amorphous status when the thickness was from 18 to 42 nm. The saturation magnetization (M_s) and low-frequency alternate-current magnetic susceptibility (χ_ac) revealed a thickness effect owing to the nano-magneto crystalline anisotropy. The H_c value was smaller than 2 Oe due to the small grain size distribution. The increased surface roughness could induce a greater pinning effect of the domain wall. The 90-mm thickness had the highest χ_ac 0.27 value at an optimal resonance frequency (f_res) of 100 Hz. The highest surface energy was 44.72 mJ/mm² at 42 nm and demonstrated high adhesion. The transmittance decreased from 13.1% to 0.27% because the thicker thickness and interface effects inhibited the transfer of photon signals to the film, resulting in a low transmittance and high absorbance.

KEYWORDS:

• Co₄₀Fe₄₀W₂₀ thin films
• low-frequency alternate-current magnetic susceptibility (χ_ac)
• optimal resonance frequency (f_res)
• nano-magneto crystalline anisotropy
• surface energy
• transmittance percentage
• magnetic-optical recording medium applications

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Ministry of Science and Technology, under grant number MOST108-2221-E-224-015-MY3, MOST105-2112-M-224-001, and National Yunlin University of Science and Technology, under grant number 109T01.