Structure and Magnetic Properties of Co 40 Fe 40 V 20 Thin Films

et al. 2020

Applied Sciences

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When B and V are added to CoFe material, the mechanical strength and spin tunneling polarization of a CoFe alloy can be improved and enhanced by the high tunneling magnetoresistance (TMR) ratio. Based on these reasons, it is worthwhile investigating Co40Fe40V10B10 films. In this work, X-ray diffraction (XRD) showed that Co40Fe40V10B10 thin films have some distinct phases including CoFe (110), CoFe (200), FeB (130), and V (110) diffracted peaks with the strongest diffracted peak for 30 nm. The lowest low-frequency alternate-current magnetic susceptibility (χac) was detected at 30 nm because the large grain distribution inducing that high coercivity (Hc) enhances the spin coupling strength and low χac. The external field (Hext) had difficulty rotating in the spin state, hence, the spin sensitivity was reduced and the χac value decreased due to increased surface roughness. The 20 mm thickness had the highest χac 1.96 × 10−2 value at 50 Hz of an optimal resonance frequency (fres). The surface energy increased from 34.2 mJ/mm2 to 51.5 mJ/mm2 for Co40Fe40V10B10 films. High surface energy had corresponding strong adhesive performance. According to the magnetic and surface energy results, the optimal thickness is 20 nm due as it had the highest χac and strong adhesion.

Section: Appl Sci 2020 10 X For Peer Review 3 Of 13mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structure, Magnetic Property, Surface Morphology, and Surface Energy of Co40Fe40V10B10 Films on Si(100) Substrate

et al. 2020

Applied Sciences

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“…The CoFeW films showed an amorphous status when the thicknesses at 18 nm, 30 nm, 60 nm, and 90 nm. It can also be reasonably concluded that the Co 40 Fe 40 W 20 thickness will have discontinuous growth model and random arrangement of atoms, leading to amorphous state [27]. The 42 nm of the CoFeW thin film has a strong crystallization, while the other thicker and thinner films are amorphous.…”

Section: Resultsmentioning

confidence: 90%

Magnetic Properties, Adhesion, and Nanomechanical Property of Co₄₀Fe₄₀W₂₀ Films on Si (100) Substrate

Journal of Nanomaterials

et al. 2020

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In this study, a Co40Fe40W20 alloy was sputtered onto Si (100) with thicknesses (tf) ranging from 18 to 90 nm, and the corresponding structure, magnetic properties, adhesive characteristics, and nanomechanical properties were investigated. X-ray diffraction (XRD) patterns of the Co40Fe40W20 films demonstrated a significant crystalline body-centered cubic (BCC) CoFe (110) structure when the thickness was 42 nm, and an amorphous status was shown when the thickness was 18 nm, 30 nm, 60 nm, and 90 nm. The saturation magnetization (Ms) showed a saturated trend as tf was increased. Moreover, the coercivity (Hc) showed a minimum 1.65 Oe with 30 nm. Hc was smaller than 4.5 Oe owing to the small grain size distribution and amorphous structure, indicating that the Co40Fe40W20 film had soft magnetism. The low-frequency alternating current magnetic susceptibility (χac) decreased as the frequency was increased. The χac revealed a thickness effect when greater thicknesses had a large χac. The maximum χac and optimal resonance frequency (fres) of Co40Fe40W20 were investigated. The maximum χac indicated the spin sensitivity and was maximized at the optimal resonance frequency. The 90 mm thickness had the highest χac 0.18 value at an fres of 50 Hz. The contact angles of the Co40Fe40W20 films are less than 90°, which indicated that the film had a good wetting effect and hydrophilicity. The surface energy was correlated with the adhesion and displayed a concave-down trend. CoFeW films can be used as a seed or buffer layer; therefore, the surface energy and adhesion are very important. The highest surface energy was 30.12 mJ/mm2 at 42 nm and demonstrated high adhesion. High surface energy has corresponding strong adhesive performance. The increased surface roughness can induce domain wall pinning effect and high surface energy, causing a high coercivity and strong adhesion. The increase of hardness and Young’s modulus could be reasonably inferred from the thinner CoFeW films. The hardness and Young’s modulus of CoFeW films are also displayed to saturated tendency when increasing thickness.

“…Table 1 contains the abbreviations and full names of the proper nouns. In earlier studies, the magnetic and adhesion characteristics of CoFeY materials were compared to those of Cobalt Iron Vanadium (CoFeV), Cobalt Iron Tungsten (CoFeW), and Cobalt Iron Ytterbium (CoFeYb) in Table 2 [ 23 , 24 , 25 , 26 , 27 ]. In contrast to previous CoFeY films that were sputtered on Si(100) substrates to study magnetic and adhesion outcomes, the goal of this research is to produce thin films on glass substrates and also investigate optical transmittance properties.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Annealing and Film Thickness on the Specific Properties of Co40Fe40Y20 Films

Chiang³

et al. 2023

Materials

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Cobalt Iron Yttrium (CoFeY) magnetic film was made using the sputtering technique in order to investigate the connection between the thickness and annealing procedures. The sample was amorphous as a result of an insufficient thermal driving force according to X-ray diffraction (XRD) examination. The maximum low-frequency alternate-current magnetic susceptibility (χac) values were raised in correlation with the increased thickness and annealing temperatures because the thickness effect and Y addition improved the spin exchange coupling. The best value for a 50 nm film at annealing 300 °C for χac was 0.20. Because electron carriers are less constrained in their conduction at thick film thickness and higher annealing temperatures, the electric resistivity and sheet resistance are lower. At a thickness of 40 nm, the film’s maximum surface energy during annealing at 300 °C was 28.7 mJ/mm2. This study demonstrated the passage of photon signals through the film due to the thickness effect, which reduced transmittance. The best condition was found to be 50 nm with annealing at 300 °C in this investigation due to high χac, strong adhesion, and low resistivity, which can be used in magnetic fields.