Structural and mechanical properties of Au alloyed AlO sputter deposited coatings

This paper is focused on the sputtering process and on the structure, chemical composition and mechanical properties of coatings consisting of AlO dielectric matrix incorporated with increasing Au contents. The maximum Au content incorporated in the coatings was 9 at.%. Al was in deficient values in relation to the Al2O3 compound. AlO matrix is amorphous irrespectively of the annealing temperature and no signs of Au crystals were detected in the as-deposited films. Segregation of small Au clusters was found in the high Au content coatings after annealing at increasing temperatures. Hardness values were in the range 11–13 GPa irrespectively of the Au content and the annealing treatments. Au clustering in the dielectric matrix, which could be able to promote surface plasmon resonance effect, associated with good mechanical properties of the AlO matrix, make envisaging the application of these coatings in decorative fields.