Exploring the Correlation Between Surface Roughness, Surface Energy, Nano-indentation, Electrical Properties, and Magnetic Characteristics of Annealed Co40Fe40Dy20 Thin Films Deposited on Si(100) Substrates.

The impact of film thickness and annealing temperature on the structural, electrical, magnetic, and mechanical properties of cobalt–iron–dysprosium (Co₄₀Fe₄₀Dy₂₀) thin films deposited on Si(100) substrates have been investigated. X-ray diffraction (XRD) analysis confirmed the film's crystalline microstructure, featuring dysprosium oxide, Dy₂O₃(440), and cobalt oxide, Co₂O₃(422) and Co₂O₃(511), crystallographic phases. Surface energy measurements indicated a noticeable reduction in surface energy following annealing treatments, which could be ascribed to the alleviation of residual stress and enhanced atomic arrangement, resulting in a more stable film structure with reduced surface energy. The film exhibited a decreasing trend in hardness with increasing thickness, and film resistivity was significantly responsive to alterations in thickness and annealing temperature. Notably, the Co₄₀Fe₄₀Dy₂₀ film demonstrated exceptional characteristics, featuring a high saturation magnetization (Ms) of 675 emu/cm³ and a low coercivity (Hc) of 9.5 Oe. Further analysis of magnetic domains and hysteresis loops revealed that larger and brighter domains were associated with higher Hc. To sum up, the surface roughness of CoFeDy films under various annealing temperatures played a pivotal role in shaping their magnetic, electrical, adhesive, and optical characteristics. An improved low-frequency alternating current magnetic susceptibility (χ_ac) value was achieved by minimizing the pinning effect on domain walls through surface smoothing. Moreover, smoother surfaces displayed heightened carrier conductivity, resulting in a decrease in electrical resistance. On the whole, Co₄₀Fe₄₀Dy₂₀ films exhibited outstanding soft magnetic properties, encompassing high saturation magnetization, low coercivity, exceptional mechanical attributes, and decreased surface energy. [ABSTRACT FROM AUTHOR]