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A composition-spread Cu-Zr thin film library with Zr contents from 2.5 up to 6.5 at.% was synthesized by magnetron sputtering on a thermally oxidized Si wafer. The compositional and microstructural variations of the Cu-Zr thin film across the composition gradient were examined using energy dispersive X-ray spectroscopy, X-ray diffraction, and high-resolution scanning and transmission electron microscopy of cross-sections fabricated by focused ion beam milling. Composition-dependent hardness and elastic modulus values were obtained by nanoindentation for measurement areas with discrete Zr contents along the composition gradient. Similarly, the electrical resistivity was investigated by 4-point resistivity measurements to study the influence of Zr composition and microstructural changes in the thin film. Both, the mechanical and electrical properties reveal a significant increase in hardness and resistivity with increasing Zr content. The trends of the mechanical and functional properties are discussed with respect to the local microstructure and composition of the thin film library.

A combinatorial science approach is utilized to study the microstructural and mechanical properties of metastable copper‑tungsten solid solutions. Lateral compositional gradient (also called composition-spread) samples were deposited by simultaneously sputtering copper and tungsten targets positioned obliquely at opposite ends of a silicon substrate. The chemical composition of the film varies continuously along its length from 12 to 45 atomic % copper and has a nominal thickness of 1 μm. Nanoindentation was performed to measure the hardness and elastic modulus of the film. Grain size and solid solution strengthening models are applied to interpret the hardness of the film, though a simple rule of mixtures is found to give a more satisfactory fit to the data. The elastic modulus of the film is consistently below that predicted by the rule of mixtures. X-ray diffraction revealed plane spacing less than that predicted by Vegard's law as well as three chemical compositions exhibiting enhanced long-range order. Transmission electron microscopy analysis confirms that the film consists of a single metastable body centred cubic solid solution where the lattice spacing and grain size depend on chemical composition.

The mechanical properties and deformation mechanisms of nano-porous ZnO thin films electrodeposited on glass substrates were determined by nanoindentation and in situ scanning electron microscope (SEM) micropillar compression. The intragranular nature of the nanoscale porosity within the individual mono-crystals of the films was probed at nano- and micro-scales for determining their mechanical response. The hardness (3.5 GPa) and reduced elastic modulus (65 GPa) of the compact thin film were found to decrease by increasing the intragranular porosity controlled by the electrochemical deposition potential of ZnO. Focused ion beam (FIB) cross-sections of residual imprints reveal that the decrease in hardness and elastic modulus observed is primarily due to compaction of the nano-porous structure. In situ SEM compression of FIB machined micropillars reveals brittle fracture and near theoretical strengths in the compact film (~ 2 GPa), and a higher flaw tolerant response despite lower failure stress in the most porous film.