【摘要】 本文采用FelNiCo(KOV)触媒,在国产六面顶压机上,利用温度梯度法首次成功生长出尺寸约4mm的优质Ⅱa型无色透明的宝石级金刚石单晶。并通过对宝石级金刚石合成过程中除氮剂性质的研究,除氮剂添加量对生长晶体的影响,优质Ⅱa型宝石级金刚石单晶生长速度的控制等,介绍了在国产六面顶压机上生长Ⅱa型金刚石单晶的相关技术。实验结果表明,为了降低金刚石内部氮的含量,生长优质Ⅱa型金刚石单晶,需在合成腔体内部加入一定含量的除氮剂-钛。钛的含量在1wt%以上时的除氮效果较好,但钛添加过量(大于2wt%)又影响晶体生长的质量。更多还原

【Abstract】 High quality type-Ⅱa diamond crystals were synthesized using FeNiCo(KOV) alloy as the solvent metal in a cubic press. Large crystals of type-Ⅱ a diamond ( about 4mm) were firstly grown by means of temperature gradient method (TGM) at high pressure and high temperature. And through the research of nitrogen getter character and the effect of the nitrogen getter on the growth of the diamond crystals, the technology of growing type-Ⅱ a diamond crystals was introduced. Experimental results showed that, in order to reduce the content of nitrogen in diamond crystal so that to obtain type-Ⅱ a diamond , a certain amount of additive Ti as nitrogen getter should be added into the synthesis capsule. The optimum content of additive Ti is lwt%. When the content of additive is more than 2wt% , it will affect the quality of gem grade diamond.更多还原