Fabrication and thermal evolution of nanoparticles in SiO2 by Zn ion implantation

SiO2 samples were implanted with 45 keV Zn ions at doses ranging from 5×1015 to 1.0×1017 ions/cm2, and were then subjected to furnace annealing at different temperatures. Several techniques, such as ultra-violet–visible spectroscopy (UV–vis), grazing incidence X-ray diffraction spectroscopy (GXRD) and atomic force microscopy (AFM), have been used to investigate formation of nanoparticles and their thermal evolution. Our results clearly show that Zn nanoparticles could be effectively formed in SiO2 at doses higher than 5×1016 ions/cm2. The subsequent thermal annealing at oxygen ambient could induce the growth of Zn nanoparticles at intermediate annealing temperature range. While at temperature above 600 °C, Zn nanoparticles could be transformed into ZnO, or even Zn2SiO4 nanoparticles. The results have been tentatively discussed in combination with Zn diffusion and migration obtained by Rutherford backscattering spectroscopy (RBS) measurements.