Laser annealing of sapphire with implanted copper nanoparticles

Copper nanoparticles have been synthesized by ion implantation in sapphire at 40 keV to a dose of 1 x 10(17) ion/cm(2), at a current density from 2.5 to 12.5 muA/cm(2). The samples were treated using pulses of a high-power Kr F excimer laser (248 nm) in ambient atmosphere. This employed a single (25 ns) pulse fluence of 0.3 J/cm(2) for Cu-implanted sapphires. Number of puls es of the same energy density and at a frequency of 1 Hz were accumulated i n the same area on the surface. The formation and modification of metal nan oparticles were assessed via optical reflectance. Generally, changes induce d by laser pulses suggest that there are reductions of the size of the nano particles without diffusion of metal atoms inward the sapphire. No evidence for oxidization of Cu nanoparticles was founded. (C) 2001 Elsevier Science B.V. All rights reserved.