Preparation and characterization of nano Au/Al₂O₃ composite thin films

Nano Au/Al₂O₃ composite thin films were successfully fabricated by a sol-gel process. The morphology, mircostructure and optical properties of the films were investigated via atomic force microscope (AFM), X-ray diffractometer (XRD), X-ray photoelectron spectrum (XPS), and UV-vis optical absorption spectrum. The Au particles, of diameter 23.2-25.7nm based on the sintering temperatures used, were found to be well dispersed in the matrix Al₂/O₃, with a very small amount of the particles escaped from the film. The surfaces of the films were uniform, compact and crack-free. The films had strong optical absorption. The peak position was related to the sintering temperature, and the intensity increased with the increase of the sintering temperature and Au contents.