Abstract
Au/Al 2 O 3 nanocomposite films, studied in this work, were prepared by RF-magnetron sputtering technique on glass substrate at room temperature under two different argon pressures, and subsequent heat treatment. Formation of gold nanoparticles was confirmed by X-ray diffraction patterns and UV-visible absorption spectroscopy. Au fill fraction f, changed from f=10.78% to f=25.45%, when argon pressure increased from 2x10 -3 mbar to 10x10 -3 mbar. For the as-deposited samples, reduction in volume fraction of gold particles causes a decrease in particle size, a lattice expansion and a blue-shift of the SPR peak position. An opposite trend is observed in the lattice parameter with respect to the gold volume fraction for the annealed samples. A small change in the sizes is observed and no significant shift of band absorption peak in samples of low Au content. However, at higher Au concentration, an appreciable red shift of the surface plasmon resonance with increasing temperature is observed. Experimental optical absorption spectra of all the samples were theoretically simulated by Maxwell–Garnett effective medium theory.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have