Ion-induced optical response of nanocomposites in sapphire

Spectra of the optical transmission of Al2O3 were measured during implantation of 60 keV Cu− ions at ion fluxes from 5 to 50 μA/cm2, to monitor formation of Cu nanoparticles. The precipitation threshold is flux-dependent. The formation of nanoparticles is (a) efficient up to a fluences of 2 × 1017 ions/cm2 and (b) most efficient for a flux of 50 μA/cm2. Intrinsic size effects have little influence on the linear and non-linear optical absorption of nanocomposites.