Optical Properties of Amorphous Metallic Alloys

Abstract

The optical properties of amorphous films of ${\mathrm{Au}}_{1\ensuremath{-}x}{\mathrm{Si}}_{x}$ alloys were studied in the spectral range from 0.01 to 6.2 eV as a function of composition in the range $0.13<~x<~0.50$. Because the electronic relaxation times are extremely short, Drude behavior dominates the entire spectrum. The onset energy of interband transitions increases on alloying with Si. In comparison with pure gold a dramatic decrease in strength of the transitions from the $d$ bands to the Fermi surface is observed in all the alloys.