Tunable absorption of Au-Al_(2)O_(3) nanocermet thin films and its morphology

摘要

The morphology of Au-Al_(2)O_(3) nanocermet thin films, prepared by cosputtering Au and Al_(2)O_(3) on float glass substrates, was studied using surface sensitive x-ray scattering techniques and the results were correlated with the optical absorption of the films measured using ultraviolet visible spectroscopy. The presence of gold nanoparticles in an alumina matrix is evident from both x-ray scattering and spectroscopic studies. The distribution of nanoparticles is obtained from grazing incidence small angle x-ray scattering, while the electron density profile obtained from the analysis of x-ray reflectivity data gives total film thickness, volume fraction (f) of Au and the special arrangement along the growth direction. Optical properties show a linear dependence of the absorption peak position with f, which is interesting for making nanocomposites of tunable absorption.