Signature of surface energy dependence of partial dislocation slip in a gold nanometer-sized protrusion

The mechanical behavior of metallic nanowires has been intensively studied, demonstrating the strong sample-size dependence of crystal plasticity. However, the effect of surface energy has not yet been fully resolved. Here we have used in situ high-resolution transmission electron microscopy of gold nanometer-sized protrusions at room temperature to address this problem. Our experimental results reveal that the slip of Shockley partial dislocations reduces the energy cost of creating the extra surface area resulting from the dislocation slip (i.e. surface steps).

► Here we show strong surface-energy dependence of crystal plasticity of a nanostructure.
► In situ HRTEM of a gold nanoprotrusion at room temperature at the atomic scale.
► The slip of Shockley partial dislocations is determined to reduce surface energy.