Geometrical constraints on the bending deformation of Penta-twinned silver nanowires

Abstract

Penta-twinned and single crystal silver nanowires were bent in-situ for TEM structural analysis using high spatial resolution scanning precession electron diffraction. Machine learning methods were used to determine the structure of the localised bends in the wires. Single crystal nanowires showed both dispersed large radius bend deformation and abrupt, angular bends with narrow deformation zones accommodated by a high angle boundary plane. The penta-twinned wires were found to display simple in-plane bends with narrow deformation zones in all 5 sub-crystals of the wire, with a common boundary plane. A coincident site lattice model has been developed to explain the bending angles seen in individual nanowires and the observed distribution of angles in a population of penta-twinned nanowires. The geometrical constraints of the model explain the difference in this distribution when compared to that from a population of single crystal nanowires.