Nanoindentation study of the mechanical properties of copper-nickel multilayered thin films

Abstract

The mechanical properties of multilayered Cu-Ni thin films with bilayer thicknesses of 1.6–12 nm were investigated by a nanoindentation technique. Force-displacement curves generated during loading and unloading of a diamond tip indenter were used to determine the hardness and elastic properties of the films. No enhancement in the elastic properties (supermodulus effect) was seen, but an enhancement in the hardness was observed. It is suggested that the enhancement, which displayed a Hall–Petch-type behavior, can be understood as owing to dislocation pinning at the interfaces analogous to the mechanism of grain boundary hardening.