Surface Orientation Strengthening in Metallic Nanowires

TL;DR

This paper investigates how surface orientation affects the strength of metallic nanowires, revealing two dislocation nucleation modes and their energetic differences, which influence nanowire mechanical properties.

Contribution

It uncovers the strong dependence of nanowire strength on surface orientation and identifies two distinct dislocation nucleation modes with differing activation energies.

Findings

Surface orientation significantly influences nanowire strength.

Two dislocation nucleation modes: corner and surface nucleation.

Activation energy for surface nucleation is higher than for corner nucleation.

Abstract

Due to the large free surface and strong anisotropy, the mechanical property of nanowire differs from its bulk counterpart. In this paper, the strong dependence of NW's strength on its surface orientation is revealed, and two modes of dislocation nucleation have been identified: the corner nucleation and the surface nucleation. The activation energy and activation volume of surface nucleation are much larger than those of the corner nucleation. The intersection line between lateral surface and {111}-type slip plane causes the discrepancy of the nucleation modes for the first dislocation.