다이아몬드 기상합성에서 과량의 수소존재하에서 H2-CH4 및 H2-CF4, H2-CH3Cl 및 H2-CS2계의 반응온도에 대한 열역학적 평형조성이 계산되었다. 산소 및 질소원료가 첨가된 경우 반응생성물로서 기체 화학종뿐만 아니라 고체상의 흑연 조성의 변화도 계산되었다. 평형조성에서 아세틸렌 및 메틸 라디칼의 농도를 최대로 유지하기 위한 반응온도는 약 2,000K 근처로 나타났다. H2-CF4 및 H2-CH3C1계에서는 HF 및 HC1 형성반응이 열역학적으로 유리하게 나타났다. 반응생성물인 고체상 흑연의 평형조성은 산소기체의 존재 유무에 가장 크게 영향을 받는 것으로 나타났다.
The thermodynamic equilibrium compositions of H2-CH4, H2-CF4, H2-CH3Cl, and H2-CS2 systems used in the vapor-phase synthesis of diamond were calculated as a function of temperature in the presence of excess H2 gas. The composition changes of solid-phase graphite as well as gas species were also investigated, when oxygen and nitrogen sources were incorporated into the systems. It was proved that the reaction temperature to maintain the maximum amount of C2H2 and CH3 species in the equilibrium compositions was about 2,000K. In the H2-CF4 and H2-CH3Cl systems, the formation reactions of HF and HCl were thermodynamically favorable. The equilibrium composition of solid-phase graphite reaction product was affected most strongly by the presence of oxygen sources.
[References]
Badzian AR, Bachmann PK, Hartnett T, Badzian T, Messier R, "Diamond Thin Films Prepared by Plasma Chemical Vapor Deposition Processes," pp. 63-77 in Proceedings of the European Research Society Meeting, Vol. XV, Les Addtions de Physique, Paris, France, 1987
Orlov YL, "The Mineralogy of the Diamond," Ch. VI, Properties of Diamonds, pp. 107-53, Wiley, New York, 1977
Bermann R, "Thermal Properties," pp. 3-22 in the Properties of Diamond, Academic Press, New York, 1979
Field JE, "Strength and Fracture Properties of Diamond," pp. 282-324 in the Properties of Diamond, Academic Press, New York, 1979
Yoder MN, "Synthetic Diamond, Its Properties and Synthesis," pp. 315-26 in Novel Refractory Semiconductors, Materials Research Society, Pitts-burgh, PA, 1987