【摘要】 本文利用纯铁粉末 (α -Fe ,纯度为 99 9% )作触媒在国产六面顶压机上进行了金刚石单晶的合成 ,研究了高温高压条件下 ( 5 7GPa ,13 70℃～ 165 0℃ ) ,石墨碳—纯铁体系中金刚石单晶的生长特性。通过光学成像显微镜观测表明 ,合成出的金刚石单晶呈浅黄色 ,晶形完整 ,且多为八面体 ,粒度约为 0 2～ 0 3mm。通过穆斯堡尔谱对晶体内部的杂质进行了测试分析 ,发现合成样品中除有少量的α -Fe外 ,其杂质的主要成分为碳化铁 (Fe3C)。我们根据Fe -C相图对碳化铁形成的机理进行了分析。认为 :由于Fe -C相互作用较强 ,在金刚石生长过程中 ,Fe元素容易以包裹体的形式进入金刚石内部。在降温的过程中 ,金刚石内部分离形式的Fe和C以碳化铁的形式出现更多还原

【Abstract】 In this paper, diamond crystals were synthesized using pure iron powder （α-Fe） as catalyst in cubic multi-anvil high pressure apparatus. The growing characteristics of diamond at 5.7GPa 1370℃～1650℃ in the graphite-pure iron system was studied. The synthesized crystals showed pale yellow color and well octahedron shape within the size of 0.2～0.3 mm. The impurities in the crystals were investigated by Mssbauer spectroscopy. The analysis results showed that the impurities in the diamond are mainly iron carbide （Fe₃C） and a few α-Fe. Based on the Fe-C phase diagram, the forming mechanism of Fe₃C in diamond was analyzed. It is suggested that, because of the strong action of Fe-C, Fe tends to stay in diamond during its growth. As the temperature drops, the included Fe and C will be combined into Fe₃C.更多还原