Diamond growth from a CO/CH4 mixture by laser excitation of CO: Laser excited chemical vapor deposition

We report for the first time, diamond growth from a mixture of 95% CO and 5% CH4 without gas phase hyperdilution of H2. Such a mixture has not been previously reported to yield diamond by any of the existing methods (hot-filament chemical vapor deposition, plasma-assisted chemical vapor deposition, or flame synthesis). In this paper we describe our observations of diamond growth at low pressures from vibrational excitation of CO in a CO/CH4 mixture by irradiation from a CO laser operating on its shorter wavelengths. We refer to this technique as laser excited chemical vapor deposition.