Structural and mechanical properties of Au alloyed AlO sputter deposited coatings

► Nanocomposite films of Au clusters in an Al-O matrix were reactive-sputtered. ► The chemical composition, structure and mechanical properties were studied. ► Au clusters were found in the coatings with higher Au contents after annealing. ► Hardness values between 11-13 GPa irrespectively of the Au content and temperature.