Formation of Core–Shell Bimetallic Nanostructures in Alkali Silicate Glasses in the Course of Silver and Copper Ion Exchange and Thermal Treatment

Abstract

Experimental data on the formation of the core–shell bimetallic spherical nanostructures in alkali silicate glasses is presented. The Ag–Cu and Cu–Ag core–shell bimetallic spherical nanostructures were formed in the near-surface glass layers by the successive Na+ → Ag+ and Na+ → Cu+ or Na+ → Cu+ and Na+ → Ag+ ion exchange and subsequent thermal treatment above the glass transition temperature. The optical density measurements have shown that the Ag–Cu core–shell nanostructures provide three plasmon resonances and the Cu–Ag core–shell nanostructures provide at least four plasmon resonances. Experimental results obtained are confirmed by computer simulation in the dipole quasistatic approximation.