A preliminary study of the growth of diamond by vapor deposition has been carried out using diamond powder and labelled methane
1313CH
4O. The powder substrate pre-treated with hydrogen was heated to temperatures of 800-990°C in a closed reaction chamber filled with
13CH
4O at 1-10 Torr initial pressure. Considering the isotope shift of the Raman lines of diamond and disordered carbon, the following has been noted from the Raman spectra of such powders. Highly disordered carbon is always deposited on the surface of diamond particles treated under the described conditions. A spectrum indicating the presence of a small amount of diamond composed of
13C is found with the powder heated in 1 Torr
13CH
4O at 800°C for 45hrs. At 10 Torr and 830°C, the deposit appears to consist entirely of disordered carbons; no indication of deposited diamond is found. Surface graphitization of the substrate occurs when heated in 1 Torr
13CH
4O at 990°C.
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