Mechanical property of metallic nanowires: the shorter is stronger and ductile

Optimal design of microelectromechanical devices requires tuning both the size and length scales of their nanocomponents, however the length effect on mechanical behavior of small crystals remains poorly understood. Here, in situ nanomechanical testing reveals a remarkable length-dependent mechanical property in silver nanowires, where both the strength and ductility display a net increase with the length reduction. Quantitative analysis shows that reduction of crystal size and crystal length could induce a completely-opposite strengthening in metallic nanowires due to the distinct operating mechanisms. These findings provide new insights into the size-dependent deformation in metallic nanowires, holding important implications for designing durable nanostructures/nanodevices.