用过剩压法生长金刚石过程石墨再结晶现象的研究

STUDIES ON THE RECRYSTALLIZATION OF GRAPHITE DURING THE PROCESS OF DIAMOND GROWTH UNDER EXCESS PRESSURE

描述了在过剩压驱动下金刚石晶种外延生过程中，大量伴生的石墨再结晶现象。再结晶石墨抑制了金刚石的自发成核；它们分布于合成腔触媒金属的低温区，结晶数量多，晶粒片状分层，尺寸大，但出现乱层晶体结构；同时产生一定数量的无定形碳。分析认为，这与长时间的低过剩压驱动，触媒金属内有足够的碳源供给，并具备在高温高压下石墨充分结晶但又达不到完全石墨化条件有关。还讨论了在低过剩压驱动下，促进金刚石晶体外延生长的碳源可能是活化的碳原子而不是具有乱层结构特征的再结晶石墨。

Characteristics of co growing of recrystallized graphite have been reported during the epitaxial growth process of diamond seed under excess pressure.Spontaneous diamond nucleation was inhibited by recrystallized graphite grains which abundantly distributed in lower temperature zone of metal solvent discs.Numerous recrystallized graphite grains,which were in strata structure but disordered each other,occured with some amorphous carbon.Those phenomina have been considered to be related to the condition under long time lower excess pressure:plentiful carbon in metal solvent discs,high temperature and high pressure are suitable for well recrystallization but insufficient for graphitization.It has also been discussed that the active carbon atoms rather than recrystallized graphite grains might play as a source of carbon for epitaxial growth of diamond under lower excess pressure.