Nucleation on an Intermediate Layer of Graphite

The prevailing view on the role of graphite particles is that graphite formation competes with diamond formation and is to be avoided, However, enhancement of diamond nucleation on graphite powder, graphite fiber,graphite disk,l l and graphite has been 

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Homogeneous nucleation of diamond in the gas phase and its contribution to different deposition processes are poorly understood. A limited number of experiments have been conducted to examine the homogeneous nucleation at atmospheric and subatmospheric pressures. The number of diamond particles collected from the gas phase is very small compared to typical surface nucleation densities. Therefore, the homogeneous nucleation mechanism cannot account for the large variety of nucleation densities observed on different substrate materials and from different surface pretreatments. Whether and how the diamond particles formed in the gas phase could serve as seeds on the substrate surface for subsequent growth of a diamond film remain unknown. 

Type of interlayer Thickness of interlayer Deposition method Tr ( C) Ts CC) CH4 in H2 (vol. %) Gus How rate (seem) P Substrate Substrate (lorr) pretreatment material  

SiC 10 nm 1277] MW PACVD 950 0.3-1CH4 0,202 200 30 polished with 0.25 pm diamond paste, ultrasonically cleaned in meihant and DI water Si 

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