Growth of diamond on diamond substrates in presence of an alkali and metal under hydrothermal conditions

Evidence of diamond growth was observed on a type II-A single crystal diamond in the “hydrothermal” pressure-temperature regime (1.4 kbars at 800 °C) in which both NaOH and Ni were added. The features seen in the SEM appear to be randomly oriented overgrowths ranging in size from 2–5 μm on the surface of a single crystal diamond. The Raman spectrum with the beam focused on these overgrown crystallites showed a sharp band at 1331 cm−1, providing further evidence of diamond growth on a single crystal diamond under pressure-temperature hydrothermal conditions.