This study investigated Co₄₀Fe₄₀W₂₀ single-layer thin films according to their corresponding structure, grain size, contact angle, and surface energy characteristics. Co₄₀Fe₄₀W₂₀ alloy thin films of different thicknesses, ranging from 10 to 50 nm, were sputtered on Si(100) substrates by DC magnetron sputtering. The thin films were annealed under three conditions: as-deposited, 250 °C, and 350 °C temperatures, respectively. The Scherrer equation was applied to calculate the grain size of Co₄₀Fe₄₀W₂₀ thin films. The results show that the grain size of CoFe(110) increased simultaneously with the increase of post-annealing temperature, suggesting that the crystallinity of Co₄₀Fe₄₀W₂₀ thin films increased with the post-annealing temperature. Moreover, the contact angles of all Co₄₀Fe₄₀W₂₀ thin films were all less than 90°, suggesting that Co₄₀Fe₄₀W₂₀ thin films show changes in the direction of higher hydrophilicity. However, we found that their contact angles decreased as the grain size of CoFe increased. Finally, the Young equation was applied to calculate the surface energy of Co₄₀Fe₄₀W₂₀ thin films. After post-annealing, the surface energy of Co₄₀Fe₄₀W₂₀ thin films increased with the rising post-annealing temperature. This is the highest value of surface energy observed for 350 °C. In addition, the surface energy increased as the contact angle of Co₄₀Fe₄₀W₂₀ thin films decreased. The high surface energy means stronger adhesion, allowing the formation of multilayer thin films with magnetic tunneling junctions (MTJs). The sheet resistance of the as-deposited and thinner CoFeW films is larger than annealed and thicker CoFeW films. When the thickness is from 10 nm to 50 nm, the hardness and Young’s modulus of the CoFeW film also show a saturation trend.

Co₆₀Fe₂₀Sm₂₀ thin films were deposited onto glass substrates in a high vacuum setting. The films varied in thickness from 10 to 50 nm and underwent annealing processes at different temperatures: room temperature (RT), 100, 200, and 300 °C. Our analysis encompassed structural, magnetic, electrical, nanomechanical, adhesive, and optical properties in relation to film thickness and annealing temperature. X-ray diffraction (XRD) analysis did not reveal characteristic peaks in Co₆₀Fe₂₀Sm₂₀ thin films due to insufficient growth-driving forces. Electrical measurements indicated reduced resistivity and sheet resistance with increasing film thickness and higher annealing temperatures, owing to hindered current-carrier transport resulting from the amorphous structure. Atomic force microscope (AFM) analysis showed a decrease in surface roughness with increased thickness and annealing temperature. The low-frequency alternating current magnetic susceptibility (χ_ac) values increased with film thickness and annealing temperature. Nanoindentation analysis demonstrated reduced film hardness and Young’s modulus with thicker films. Contact angle measurements suggested a hydrophilic film. Surface energy increased with greater film thickness, particularly in annealed films, indicating a decrease in contact angle contributing to this increase. Transmittance measurements have revealed intensified absorption and reduced transmittance with thicker films. In summary, the surface roughness of CoFeSm films at different annealing temperatures significantly influenced their magnetic, electrical, adhesive, and optical properties. A smoother surface reduced the pinning effect on the domain walls, enhancing the χ_ac value. Additionally, diminished surface roughness led to a lower contact angle and higher surface energy. Additionally, smoother surfaces exhibited higher carrier conductivity, resulting in reduced electrical resistance. The optical transparency decreased due to the smoother surface of Co₆₀Fe₂₀Sm₂₀ films.

The growth rate and the growth mechanism are investigated by examining the results of scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) on TiO₂ nanorods fabricated in the second anodization process through the nanopores of anodic aluminum oxide. Due to the strong electric field of 1.86 GV/m to 1.33 GV/m, the average ultra-fast growth rate of 250 nm/s is observed, and the abrupt increase of height reaches to 85.2% of its destined height in the early growth stage of 0.6 s. Then the growth rate decreases when the electric field decays with the increase of height, and it is interrupted by the dielectric breakdown under an electric field of 0.65 GV/m. According to the XPS analyzes, the TiO₂ species on the outer shell of nanorods are observed, and the sub-oxides, Ti₂O₃ and TiO, are exhibited after Ar⁺ ions sputtering. It is proposed that the bottom growth mechanism is identified by the analyzes upon SEM and XPS results.

In this study, Co₄₀Fe₄₀B₁₀Dy₁₀ thin films were deposited using a direct current (DC) magnetron sputtering technique. The films were deposited on glass substrates with thicknesses of 10, 20, 30, 40, and 50 nm, and heat-treated in a vacuum annealing furnace at 100, 200, and 300 °C. Various instruments were used to examine and analyze the effects of roughness on the magnetic, adhesive, and mechanical properties. From the low frequency alternating current magnetic susceptibility (χ_ac) results, the optimum resonance frequency is 50 Hz, and the maximum χ_ac value tends to increase with the increase in the thicknesses and annealing temperatures. The maximum χ_ac value is 0.18 at a film thickness of 50 nm and an annealing temperature of 300 °C. From the four-point probe, it is found that the resistivity and sheet resistance values decrease with the increase in film deposition thicknesses and higher annealing temperatures. From the magnetic force microscopy (MFM), the stripe-like magnetic domain distribution is more obvious with the increase in annealing temperature. According to the contact angle data, at the same annealing temperature, the contact angle decreases as the thickness increases due to changes in surface morphology. The maximal surface energy value at 300 °C is 34.71 mJ/mm². The transmittance decreases with increasing film thickness, while the absorption intensity is inversely proportional to the transmittance, implying that the thickness effect suppresses the photon signal. Smoother roughness has less domain pinning, more carrier conductivity, and less light scattering, resulting in superior magnetic, electrical, adhesive, and optical performance.

In this study, a 10–50 nm Co₃₂Fe₃₀W₃₈ alloy thin film sputtered on glass substrates was annealed at different temperatures for 1 h including room temperature (RT), 300, 350, and 400 °C. The structure, magnetic properties, surface energy, and optical properties of the Co₃₂Fe₃₀W₃₈ alloy were studied. X-ray diffraction (XRD) patterns of the as-deposited Co₃₂Fe₃₀W₃₈ thin films showed the amorphous structure. The apparent body-centered cubic (BCC) CoFe (110) structure was exhibited after 300 °C annealing for 1 h. The 300 °C annealed Co₃₂Fe₃₀W₃₈ thin film showed the highest CoFe (110) peak compared with other temperatures. Furthermore, the thicker the Co₃₂Fe₃₀W₃₈ thin film, the higher the CoFe (110) peak. The CoFe (110) peak revealed magneto-crystalline anisotropy, which was related to the strong low-frequency alternative-current magnetic susceptibility (χ_ac) and induced an increasing trend of saturation magnetization (M_s) as the thickness (t_f) increased. Due to the thermal disturbance, the χ_ac and M_s for the 350 and 400 °C annealed Co₃₂Fe₃₀W₃₈ thin film decreased. The contact angles of the Co₃₂Fe₃₀W₃₈ thin films were less than 90°. For all temperatures, the surface energy increased when the film thickness increased from 10 to 50 nm. In addition, the surface energies for annealed samples were comparatively higher than the as-deposited samples. The higher surface energy of 28 mJ/mm² was obtained for the 50 nm Co₃₂Fe₃₀W₃₈ thin film annealed at 300 °C. The transmittance percentage (%) of the as-deposited Co₃₂Fe₃₀W₃₈ film was higher than other annealed conditions. This result contributed to the fact that higher crystallization, due to perfect band structures, may inhibit the transmission of photon signals through the film, resulting in low transmittance and high absorption.