Nanoindentation of single crystal and polycrystalline copper nanowires

Metal nanowires are attracting considerable interest because of their potential importance to the technology of miniaturization of electronic devices in need of metallic contacts. One of the important attributes of nanowires is their potentially high mechanical strength. Nanoindentation is the most realistic tool at the present time to determine the mechanical properties of nanowires. The load-displacement behavior during nanoindentation of electrodeposited single crystal and 500 nm diameter polycrystalline copper nanowires was performed and the results are reported in this paper. The behavior has also been compared with that of bulk nanocrystalline and annealed copper. The hardness values for 50 nm grain size polycrystalline nanowires and those of extruded bulk 50 nm grain size copper were comparable, 2.1 GPa, and that of a 50 nm single crystal copper nanowire was 1.8 GPa.