Growth of c-diamond, n-diamond and i-carbon nanophases in carbon-ion-implanted fused quartz

Abstract Combined high-resolution transmission electron microscopy, selected-area electron diffraction and parallel electron-energy-loss spectroscopy are used to characterize nanophases of carbon found embedded in fused quartz. These appear after implantation of 1 MeV carbon ions, followed by annealing in argon, oxygen and forming gas for lh at 1100°C. For argon, virtually all the carbon diffuses out of the substrate with no observable carbon clusters for all doses studied. After annealing in oxygen, a crystalline CO x phase is identified at the end of range, following a dose of 5 × 1017 carbon ions cm−2. Three nanocrystalline carbon phases, including diamond, appear after annealing in forming gas; these form a layer 170 nm beneath the fused quartz surface for all ion doses. The average size of these clusters and the corresponding phases depend on the ion dose; the smallest clusters of 5-7 nm diameter crystallize as fcc Fd3m diamond following a dose of 0.5 × 1017 carbon ions cm−2, whereas clusters of 8–13...