Impact of Annealing on Magnetic Properties and Structure of Co40Fe40W20 Thin Films on Si(100) Substrate

Abstract

Co40Fe40W20 monolayers of different thicknesses were deposited on Si(100) substrates by DC magnetron sputtering, with Co40Fe40W20 thicknesses from 10 to 50 nm. Co40Fe40W20 thin films were annealed at three conditions (as-deposited, 250 °C, and 350 °C) for 1 h. The structural and magnetic properties were then examined by X-ray diffraction (XRD), low-frequency alternative-current magnetic susceptibility (χac), and an alternating-gradient magnetometer (AGM). The XRD results showed that the CoFe (110) peak was located at 2θ = 44.6°, but the metal oxide peaks appeared at 2θ = 38.3, 47.6, 54.5, and 56.3°, corresponding to Fe2O3 (320), WO3 (002), Co2O3 (422), and Co2O3 (511), respectively. The saturation magnetization (Ms) was calculated from the slope of the magnetization (M) versus the CoFeW thickness. The Ms values calculated in this manner were 648, 876, 874, and 801 emu/cm3 at the as-deposited condition and post-annealing conditions at 250, 350, and 400 °C, respectively. The maximum MS was about 874 emu/cm3 at a thickness of 50 nm following annealing at 350 °C. It indicated that the MS and the χac values rose as the CoFeW thin films’ thickness increased. Owing to the thermal disturbance, the MS and χac values of CoFeW thin films after annealing at 350 °C were comparatively higher than at other annealing temperatures. More importantly, the Co40Fe40W20 films exhibited a good thermal stability. Therefore, replacing the magnetic layer with a CoFeW film improves thermal stability and is beneficial for electrode and strain gauge applications.

Annealing Effect on the Contact Angle, Surface Energy, Electric Property, and Nanomechanical Characteristics of Co40Fe40W20 Thin Films

“…The corresponding X-ray diffraction patterns (XRD) of the CoFeW films have been proved in our previous literature [22]. From a previous study, it was indicated that the CoFe(110) peak and specific Fe 2 O 3 (320), WO 3 (002), Co 2 O 3 (422), and Co 2 O 3 (511) oxide peaks are displayed in XRD.…”

“…When the post-annealing temperature reached 350 • C, the surface energy was 36.02 mJ/mm 2 at 30 nm. According to the XRD results [22], the formation of oxide layers on the thin films' surface resulted in decreased contact angles and increased surface energy [31]. These CoFeW thin film data are shown in Table 1.…”

“…It can be widely used in magnetic and semiconductor applications. In our previous studies, the relationship between magnetism and structure of CoFeW films, as deposited and annealed, has been studied [22]. This study is an extension of our previous research to investigate contact angle and surface energy.…”

Studying the Crucial Physical Characteristics Related to Surface Roughness and Magnetic Domain Structure in CoFeSm Thin Films

“…The XRD patterns of the as-deposited and annealed Co 40 Fe 40 Sm 20 thin films are illustrated in Figure 1. Distinct peaks in the X-ray diffraction (XRD) patterns are evident at specific diffraction angles (2θ) of 47.7 • , 54.6 • , and 56.4 • , corresponding to the crystallographic planes of Co (0002), Co 2 O 3 (422), and Co 2 O 3 (511) [16,17]. Guojian Li et al fabricated Co films on Si(100) substrate and observed the layer of Co films, SiO 2 , and Si by transmission electron microscopy (TEM), with SiO 2 being the nature oxide for the Si substrate surface [18].…”