Artifact Diamond Characterization

摘要

Three CVD diamond films were produced in a hot-filament reactor using acetone asthe carbon source. The acetone was enriched 33% at the methyl carbon, and the total gas-phase concentrations were 5.3%, 6.4%, and 7.4%. Static solid-state NMR measurements of hydrogen concentration, sp2/sp3 carbon bonding environments, and carbon-13 spin-lattice relaxation have been made on these films while they remain intact on their substrates. The hydrogen concentration was found to be below 1 at. % in each film. Increasing sp2 content is found with increasing gas-phase carbon concentration. Ongoing measurements are aimed at understanding the sp3 region of the NMR spectra and its relationship to Raman measurements of these films. An increased concentration of defect centers decreased the spin-lattice relaxation time constant from 18 s to 1 s as the pas-phase carbon concentration increased.