GROWTH OF DIAMOND AND NICKEL CARBIDE CRYSTALS IN THE NI-C-H SYSTEM

Simultaneous growth of diamond and nickel carbide on a graphite substr ate was observed. Nickel carbide appeared as a non-stoichiometric inte rstitial solid solution possessing the NaCl-type structure. The nuclea tion and growth of diamond was conducted by microwave plasma chemical vapor deposition. The CH4-H-2 plasma produces intensive mass transport in the separate nickel carbide crystals resulting in coalescence. A h ypothesis of the formation of gaseous organometallic molecules is desc ribed and the role of atomic hydrogen which alters the Ni-C-H equilibr ia is discussed.