Synthesis of Nearly Monodisperse Embedded Nanoparticles by Separating Nucleation and Growth in Ion Implantation

We investigate the formation of nanoparticles of Au in SiO2 by multiple ion implantation steps and intermediate anneals to isolate nucleation and growth, thereby producing a narrow particle size distribution. We discuss the effects of varying the initial nucleation dose and the growth temperature and establish guidelines for synthesizing nanoparticles with improved size uniformity. By this method, we have obtained a standard deviation of 16% on an average diameter of 1.68 nm, compared to 28% when no attempt is made to isolate nucleation and growth.