Thermodynamic paradox of diamond deposition with simultaneous graphite etching in the low pressure synthesis of diamond: Approach by charged cluster model
- Korea Research Institute of Standards and Science, Daejon (Korea, Democratic People`s Republic of)
- Korea Advanced Institute of Science and Technology, Daejon (Korea, Democratic People`s Republic of)
If diamond deposits and graphite etches simultaneously in the low pressure synthesis of diamond, the chemical potential of carbon in diamond and in graphite would be, respectively, lower and higher than that in the gas phase. The analysis leads to diamond being more stable than graphite, contradicting the well-established stability between diamond and graphite. In the C-H system, the solubility of carbon in the gas phase is minimum at {approx} 1500 K and it increases with decreasing temperature. In the charged cluster model, diamond nucleates in the gas phase. The gas phase, being depleted of carbon by the maximum precipitation of the diamond clusters at {approx}1500 K, becomes undersaturated with carbon when supercooled to the substrate temperature and a portion of the cluster is expected to etch. The unetched portion of the diamond cluster will deposit with simultaneous etching on an atomic scale. Thus, diamond deposition with simultaneous graphite etching can be explained based on the charged cluster model without leading to the thermodynamic paradox.
- OSTI ID:
- 230135
- Report Number(s):
- CONF-950840-; TRN: 96:000433-0135
- Resource Relation:
- Conference: International conference on applications of diamond films and related materials, Gaithersburg, MD (United States), 21-24 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of Applications of diamond films and related materials: Third international conference; Feldman, A.; Yarbrough, W.A.; Murakawa, Masao; Tzeng, Yonhua; Yoshikawa, Masanori [eds.]; PB: 973 p.
- Country of Publication:
- United States
- Language:
- English
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