Thick-film SmCo5 micromagnet fabrication using molten salt

Sintered Nd-Fe-B magnets encounter thickness and shape limitations due to machining-induced degradation. Although Nd-Fe-B magnetic films show promise, achieving thicker films with complex shapes and larger sample sizes is difficult due to limitations in existing deposition methods. In this study, we successfully developed a method to fabricate a 100-μm-thick SmCo₅ micromagnet film on a complex Co structure using molten-salt processing to diffuse Sm into Co. The magnetic properties of the film were characterized using vibrating sample magnetometry measurements, revealing a zero-field magnetic flux density of ∼1.0 T and coercivity of ∼820 kA/m. The fabricated film exhibited anisotropic magnetism, with its easy magnetization axis aligned along the thickness direction. Utilizing the unique properties of the micromagnet, we then designed and fabricated a stable 1.5-mm-diameter micromotor, capable of rotating at 1,000 rpm. This study enables the fabrication of 100-μm-thick SmCo₅ micromagnets for miniaturized electromagnetic systems, offering potential applications in advanced electromechanical devices.