Determination of Mechanical Properties of Copper at the Micron Scale

Using a focused ion beam workstation, micron‐sized bending and compression samples were fabricated from a pure copper single crystal. The bending and compression experiments exhibited a strong size effect on the flow stress of copper, reaching values in the order of 1 GPa for the smallest test structures. Conventional strain gradient plasticity approaches are not capable of explaining this behaviour. The surface damage introduced by Ga⁺ ion implantation during focused ion beam preparation was investigated using Auger electron spectroscopy and its consequence on the mechanical response of the miniaturized test samples is addressed.