Effect of interparticle plasmon coupling and temperature on the optical properties of bimetallic composite nanoparticles with a core-shell structure

In this work, the optical properties of bimetal composite nanoparticles with a core-shell structure are investigated in the framework of quasi-static and Maxwell-Garnett approximation. The influence of interparticle plasmon coupling and temperature on the optical absorption of bimetallic core-shell nanoparticles is studied while the shell consists of Al and Cu particles. In fact, dependence of the optical absorption and its full width at half maximum on the dielectric constant of the core, host matrix, and embedding medium for both spherical and cylindrical bimetallic nanocomposites is shown. It was found that both the plasmonic shifting and bandwidth are dependent on the volume fraction of metal nanoparticles (filling factors) and the temperature. However, a new plasmon oscillation mode is created and observed in the spectra owing to the interparticle plasmon coupling of different metallic particles which cannot be found in a monometal nanocomposite. (C) 2015 AIP Publishing LLC.