Fe-Sb Thin Films Obtained by Thermal Evaporation of Nanostructured Milled Powder: Investigation of Structural and Magnetic Properties

Abstract

Abstract: Nanostructured Fe₉₀Sb₁₀ (wt.%) alloys were synthesized by mechanically alloying pure iron and antimony powders in a high-energy planetary ball mill. The milling duration was optimized to achieve a nanostructured mixture and form a supersaturated solid solution of α-Fe(Sb). Subsequently, thin films were fabricated through thermal evaporation (physical vapor deposition) under a vacuum of 2.1 × 10^-5 mbar, utilizing an electrically heated tungsten boat and the supersaturated solid solution α-Fe(Sb) powder obtained via mechanical alloying. The films were deposited on glass substrates. This study investigates the influence of milling time and film thickness on the structural and magnetic properties of Fe₉₀Sb₁₀ powders and thin films. Structural and magnetic characterizations were performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). The Fe(Sb) solid solution phase was identified after 12 hours of milling, with a particle size of approximately 18.16 nm with microstrain increasing to 0.19% after 36 hours. SEM analysis revealed a more homogeneous particle distribution as milling time increased. Furthermore, as the film thickness increased from 16 nm to 90 nm, a steady decrease was observed in the lattice parameter, accompanied by an increase in the average crystallite size from 5.9 nm to 16.8 nm and a slight increase in microstrain. In parallel, the coercive field dropped from 6.64 Oe to 3.05 Oe, suggesting improved magnetic softness in thicker films.

Keywords: Thin films, FeSb solid solution, Microstructure, X-ray diffraction (XRD), Vibrating sample magnetometry (VSM).