Nanomolding single-crystalline CoIn₃and RhIn₃ nanowires.

CoIn₃ and RhIn₃ are intermetallic compounds recently explored for their catalytic and topological properties. Nanostructuring could prove beneficial in the study of these compounds, due to the potential enhancement of both catalytic active sites and the surface states’ contributions at the nanoscale. Here we report the successful synthesis of CoIn₃ and RhIn₃ nanowires using thermomechanical nanomolding (TMNM), i.e. the extrusion of nanowires from polycrystalline bulk feedstock materials using a nanoporous mold. Using scanning transmission electron microscopy (STEM), we revealed the single-crystalline nature of the wires and their formation mechanism from the bulk materials. Transport measurements performed on nanowire devices, fabricated by standard e-beam lithography, reveal the metallic characters of the wires, down to the 20-nm diameter range. Density functional theory calculation reveals the possible roles of indium vacancies and surface roughness on the wires’ resistivities, which are measured to be 3-4 times the bulk values. Our study demonstrates an effective route for synthesizing intermetallic nanowires comprising elements with vast differences in melting points and vapor pressures, thus offering a promising synthesis method for studying topological materials at the nanoscale.