Ultrafast laser-induced topochemistry on metallic glass surfaces

Manufacturing multifunctional nanocomposite materials and engineered surface nanopatterns involves a strategic blend of topography, crystal structures, and chemistry. Here, we report the controllable formation of crystalline nanoparticles and intermetallic compounds on thin films of metallic glasses (Zr50Cu50, Ti50Cu50, and Zr67Ag33) irradiated by ultrafast laser beams. Mapping the structural modification of the photoexcited and subsequently heated alloys reveals previously neglected chemical reactions with air, offering a direct solution for incorporating nanoparticles into an amorphous oxide matrix and broadening the range of laser-induced surface self-organization features. Our findings are attributed to the occurrence and enrichment of oxygen surface contamination that reacts with selected elements of the metallic glasses. Additionally, the growth of the crystalline phase from undercooled liquid may originate from the dissolution of oxides. Finally, our results establish that the combination of crystalline nanoparticles on amorphous periodic patterns can be universally obtained in a wide range of binary systems of irradiated metallic glasses. •3 metallic glass thin films have been produced through PVD for irradiation by ultrafast laser•Ultrafast laser irradiation in air significantly alters the surface chemistry of amorphous alloys on 200 nm thickness•Laser-induced periodic energy confinement generates crystalline nanoparticles, tens of nanometers in size, on the crests of LIPSS•Air-induced reactions causes the most reactive metal to oxidize to its highest valence state, segregating the metallic components at the surface•Crystalline phases grow on top of amorphous thin films potentially enhancing reactivity, catalysis, and offering antibacterial opportunities