“柱状”金刚石晶体的高温高压合成

Synthesis of column-shaped diamond under HTHP

利用普通触媒和自行研制的新型触媒A,在国产六面顶压机上分别进行了合成金刚石单晶的实验。研究表明,普通粉末触媒合成出的金刚石单晶呈黄色,晶形完整,晶形是六一八面体,晶体透明度较好,并且合成出晶体的粒度比较集中,大约为0.3 mm。用新型触媒A合成的金刚石单晶呈绿色,并且晶形以长条晶体出现,长度集中在(0.5～0.7)mm。用SEM电镜观察到,前一种晶体晶形完整,表面光滑,后一种晶体表面也比较平整,存在"V"形缺陷。含氮量分析结果表明,用普通粉末触媒合成的金刚石的含氮量较低。

In this paper diamond monocrystals were synthesized using the new Fe-based type catalyst A and normal common catalyst respectively in a SPD6 × 1200 high-pressure and high-temperature apparatus. The result indicated that the diamond crystals synthesized using common catalyst show a yellow color and integrity morphology. Most of crystal is transparency. The grain size of synthesized crystal is relatively uniform and normal crystal size is 0. 3 mm. Diamond crystals synthesized using catalyst A shown green color and stripe morphology. The crystal size is 0. 5mm to 0. 7ram. This two type crystals were observed under scanning electronic microscopy （SEM）. It shown that the surface of former crystal is smooth, but the ＂V＂ shape defect can be seen on the surface of the latter. Through the FTIR spectra it can be seen that the concentration of former crystal is lower, but the latter is higher.