From lunar glass to advanced metallic glass: dense nanocrystallization catalyzed by implanted ions

• • Solar wind irradiation generates ~2 nm Fe nano-clusters within a 4 μm surface layer of lunar glass, which upon heating yield dense Fe nanocrystals, whereas unirradiated interiors form coarse crystals, demonstrating that pre-existing defects can template nanocrystallization. • • H+ ion irradiation of Fe86B14 metallic glass produces surface nanocrystals of 5–8 nm, compared to 15–20 nm in the deep interior, achieving a 2–3 fold reduction in grain size. • • The permeability at 10 kHz increases by 10.2% after H+ irradiation and nanocrystallization, directly enhancing soft magnetic performance for high-frequency applications. • • The use of ion irradiation to catalyze dense nanocrystallization offers a scalable route for refining microstructures in metallic glasses, potentially reducing core losses and improving energy efficiency in magnetic components.