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

Nanocrystallization of glasses is a critical pathway for designing advanced materials with superior properties. In this study, we investigated the crystallization behavior of lunar glasses retrieved by the Chang’E-5 mission. It was observed that solar wind irradiation induces abundant Fe nano-clusters with a size of about 2 nm within a layer of about 4 µm close to the surface. Upon heating, these defects act as nucleation sites, facilitating the precipitation of homogeneous and dense Fe nanocrystals. In contrast, the uni-rradiated interior of the lunar glass crystallizes into coarse Fe crystals. Inspired by these findings, advanced magnetic nanocrystalline alloys are designed based on Fe₈₆B₁₄ metallic glass by H⁺ ion irradiation. After H⁺ ion irradiation and nanocrystallization, the size of nanocrystals close to the surface is about 5–8 nm, which is much smaller than the nanocrystals in the deep interior (15–20 nm). The permeability at 10 kHz increases by about 10.2%. These results not only give insights into the thermal stability of lunar glasses, but also present a novel strategy for designing advanced soft magnetic materials with enhanced performance.