Mechanical properties of highly textured Cu/Ni multilayers

Abstract We report on the synthesis of highly (1 1 1) and (1 0 0) textured Cu/Ni multilayers with individual layer thicknesses, h , varying from 1 to 200 nm. When, h , decreases to 5 nm or less, X-ray diffraction spectra show epitaxial growth of Cu/Ni multilayers. High resolution transmission electron microscopy studies show the coexistence of nanotwins and coherent layer interfaces in highly (1 1 1) textured Cu/Ni multilayers with smaller h . Hardnesses of multilayer films increase with decreasing h , approach a maximum at h of a few nanometers, and show softening thereafter at smaller h . The influence of layer interfaces as well as twin interfaces on strengthening mechanisms of multilayers and the formation of twins in Ni in multilayers are discussed.