LAUSR

The next generation of power electronics necessitates materials capable of rapid response at tens of kilohertz frequencies while ensuring minimal core losses. Accelerating the advancement of power electronics hinges on addressing the current shortage of ultra-low core loss soft magnets, thereby enabling sustainable energy utilization and paving the way toward achieving zero carbon footprints. Here we demonstrate an approach that integrates nanostructure engineering with high-frequency domain structure control, significantly enhancing the performance of Fe-enriched amorphous ribbons. Our strategy reduces core loss by 55%, achieving an ultra-low loss of ~ 75 ± 1.3 W/kg at 10 kHz, 1 T. We attribute this improvement to optimized perpendicular magnetic anisotropy, which is induced by positive magnetostriction and compressive stress generated from partial nanocrystallization of α-Fe in a residual amorphous matrix. These configurations lead to the formation of a narrow stripe-shaped magnetic domain (~ 4.8 ± 0.6 μm wide), resulting in minimal excess loss. These findings highlight a pivotal advancement in soft magnet design, facilitating energy-efficient, miniaturized power electronics for modern applications. Magnetic losses are a major source of inefficiency in power electronics. Minimizing these losses requires soft magnetic materials with high saturation magnetization, low coercivity, and low core loss at high frequency. Here, Gautam et al present an approach combining nanostructure engineering with high frequency domain structure control, reducing core losses by 55%.