Pseudoelasticity and Shape Memory in Metal Nanowires
Novel shape memory effect (SME) and pseudoelastic behavior are discovered in single-crystalline Au, Cu, and Ni nanowires with lateral dimensions of 1.5-10 nm. Under tensile loading and unloading, these wires can recover elongations of up to 50%, well beyond the recoverable strains of 5-8% typical for most bulk shape memory alloys (SMAs). Results of atomistic simulations and evidences from experiments show that this phenomenon only exists at the nanometer scale and is associated with a reversible crystallographic lattice reorientation driven bythe high surface-stress-induced internal stresses at the nanoscale.This understanding also explains why these metals do not show an SME at macroscopic scales.
Novel shape memory effect (SME) and pseudoelastic behavior are discovered in single-crystalline Au, Cu, and Ni nanowires with lateral dimensions of 1.5-10 nm. Under tensile loading and unloading, these wires can recover elongations of up to 50%, well beyond the recoverable strains of 5-8% typical for most bulk shape memory alloys (SMAs). Results of atomistic simulations and evidences from experiments show that this phenomenon only exists at the nanometer scale and is associated with a reversible crystallographic lattice reorientation driven bythe high surface-stress-induced internal stresses at the nanoscale.This understanding also explains why these metals do not show an SME at macroscopic scales.
