Surface stress induced structural transformations and pseudoelastic effects in palladium nanowires

Using molecular dynamics simulations, we investigate the surface stress induced structural transformations and pseudoelastic behaviors in palladium nanowires. For wires with a ⟨100⟩ initial orientation, the simulations indicate that when the cross-sectional area is less than 2.18 × 2.18 nm 2 , the nanowire undergoes spontaneous reversible phase transformation from fcc to body-centered tetragonal structure. In wires with larger cross-sectional areas, the structural transformation is achieved via spontaneous reversible lattice reorientation. In both cases, under tensile loading and unloading, Pd nanowires reverse between the corresponding transformed structure and the original structure, exhibiting pseudoelastic behaviors characterized by fully recoverable strains of up to 50%.