Reversible chiral structure transformation of ultra-thin gold nanowire under tensile strain conditions

Behaviors of ultrathin metallic nanowires under strain conditions have attracted plenty of interest due to their unique properties and structures. Here, for the first time, we provide direct atomic-scale observations of the reversible chiral structure transformation of the gold nanowire under tensile strain conditions in transmission electron microscopy. The formation and disappearance of a (111) projection in the (110) projected nanowire were observed during the structural transformation. We reveal that the chiral structure transformation is induced by the nanowire twisting behavior, which is achieved via atomic plane rotation and nanowire bending. Our results provide direct evidence for an expressive and deterministic reversible transformation from a symmetrical face-centered-cubic structure to the chiral structure of gold nanowires, which enables an atomic-scale understanding of the behavior of ultra-thin nanostructure and provides guidance in the design of nano-devices.