Alloy plasmonic materials

We focused on the Au, Ag and Cu alloy systems and the experimental determination of their optical permittivity using optical transmission and reflection measurements with thin metal films. The optical constants define the plasmon resonance frequency and the electro-magnetic field intensity localized around the nanoparticles. However it is less known how the alloy metals perform in the field enhancement. Due to the unknown morphology and composition of the alloy, optical properties have to be determined experimentally. We demonstrate experimentally determination of the permittivity and Drude parameters of alloys and discuss the obtained results in comparison with X-ray crystallography measurements.