Optical reflectance of insulators containing implanted metal nanoparticles

Silver nanoparticles have been synthesised by ion implantation in soda-lime silicate glass at 60 keV to a dose of 7x1016 ion/cm2 at a current density of 10 μA/cm2. The silver profile distribution was determined by Rutherford backscattering spectroscopy (RBS). Optical properties of composites were characterised by reflectance measured from both the implanted and the rear face of the sample. For modelling of reflectivity spectra a multilayer structure was considered and a matrix method using complex Fresnel coefficients was applied. Dielectric permeabilities of composite layers were calculated using the Maxwell-Garnet effective medium theory. Agreement between theoretical and experimental reflectivity spectra was achieved by accounting for the non-uniform silver concentration distribution with depth in the implanted glass surface