Optical properties and plasmonic response of silver-gallium nanostructures

Silver and gallium form an alloy Ag2Ga via a room temperature spontaneous self-assembly that exhibits remarkable mechanical and electrical properties suitable for nanoscale measurements. However, whether photon excitation of plasmons in this emerging nanomaterial is retained or not has not been established. Here, we present a thin film formation of Ag2Ga via a spreading-reactive process of liquid Ga on an Ag film and a characterization of its dielectric function epsilon(E) = epsilon(1)(E) + i epsilon(2)(E) in the photon energy range 1.42 eV <= E < 4.2 eV. It is observed that while the plasmon damping increases, near an energy of 2.25 eV, the real part of epsilon exhibits a crossing with respect to that of Ag. Furthermore, the impact of new plasmon supporting materials is discussed and in order to enable further applications in plasmonics, the possibility of photon excitation of surface plasmons in Ag2Ga is studied. (C) 2015 AIP Publishing LLC.