用纳米石墨作碳源在高温高压下合成条形金刚石

在国产 6× 12 0 0吨铰链式六面顶压机上 ,选用 Fe55Ni2 9Co16粉末触媒和 Ni70 Mn2 5Co5粉末触媒 ,在 5.1GPa和 1350 K的条件下 ,首次用纳米石墨进行了金刚石的合成实验。实验结果表明 :纳米石墨在 Fe55Ni2 9Co16粉末触媒和高温高压条件下生成大小在 2 0 μm左右的条形金刚石 ;在Ni70 Mn2 5Co5粉末触媒和高温高压条件下生成大小在 5～ 2 0 μm左右的、呈六一八面体的金刚石。两种金刚石都是透明的。初步分析了条形金刚石的形成原因。

Synthesize of Needlie-like Diamond Under High-temperature and Highpressure Using Nanometric-graphite as Carbon Source

Using nanometric-graphite as carbon source and Fe55Ni29Co16 powder as catalyst, the needle-like diamond of 15μm in size can be synthesized under high-temperature and high-pressure of 1350K and 5.1GPa. However, the needle-like diamond is seldom seen in the experiments of diamond synthesis. Under the same condition, cloosing Ni70Mn25Co5powder catalyst and sample assembly, the granular diamond of 5～20μm in size can be synthesized. These two sorts of diamond are transparent. The cause of the formation of needle-like diamond is discussed in this paper. This phenomenon shows that the nanometric-graphiteparti cles can be used to syntheize diamond under lower temperature because of the surface activity of nanometric particles and nanometric scale.