Different effect of NiMnCo or FeNiCo on the growth of type-Ⅱa large diamonds with Ti/Cu as nitrogen getter  

作　　者：李尚升 张贺 宿太超 胡强 胡美华 龚春生 马红安 贾晓鹏 李勇 肖宏宇 

机构地区：[1]School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China [2]State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China [3]School of Data Science, Tongren University, Tongren 554300, China [4]Department of Mathematics and Physics, Luoyang Institute of Science and Technology, Luoyang 471023, China

出　　处：《Chinese Physics B》2017年第6期454-458,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11604246);the China Postdoctoral Science Foundation(Grant No.2016M592714);the Professional Practice Demonstration Base for Professional Degree Graduate in Material Engineering of Henan Polytechnic University,China(Grant No.2016YJD03);the Funds from the Education Department of Henan Province,China(Grant Nos.12A430010 and 17A430020);the Project for Key Science and Technology Research of Henan Province,China(Grant No.162102210275)

摘　　要：In order to synthesize high-quality type-Ⅱa large diamond, the selection of catalyst is very important, in addition to the nitrogen getter. In this paper, type-IIa large diamonds are grown under high pressure and high temperature（HPHT） by using the temperature gradient method（TGM）, with adopting Ti/Cu as the nitrogen getter in Ni70Mn25Co5（abbreviated as NiMnCo） or Fe（55）Ni（29）Co（16）（abbreviated FeNiCo） catalyst. The values of nitrogen concentration（Nc） in both synthesized high-quality diamonds are less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo or Ti/Cu（1.8 wt%） is added in the NiMnCo. The difference in solubility of nitrogen between both catalysts at HPHT is the basic reason for the different effect of Ti/Cu on eliminating nitrogen. The nitrogen-removal efficiency of Ti/Cu in the NiMnCo catalyst is less than in the FeNiCo catalyst. Additionally, a high-quality type-Ⅱa large diamond size of 5.0 mm is obtained by reducing the growth rate and keeping the nitrogen concentration of the diamond to be less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo catalyst.In order to synthesize high-quality type-Ⅱa large diamond, the selection of catalyst is very important, in addition to the nitrogen getter. In this paper, type-IIa large diamonds are grown under high pressure and high temperature（HPHT） by using the temperature gradient method（TGM）, with adopting Ti/Cu as the nitrogen getter in Ni70Mn25Co5（abbreviated as NiMnCo） or Fe（55）Ni（29）Co（16）（abbreviated FeNiCo） catalyst. The values of nitrogen concentration（Nc） in both synthesized high-quality diamonds are less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo or Ti/Cu（1.8 wt%） is added in the NiMnCo. The difference in solubility of nitrogen between both catalysts at HPHT is the basic reason for the different effect of Ti/Cu on eliminating nitrogen. The nitrogen-removal efficiency of Ti/Cu in the NiMnCo catalyst is less than in the FeNiCo catalyst. Additionally, a high-quality type-Ⅱa large diamond size of 5.0 mm is obtained by reducing the growth rate and keeping the nitrogen concentration of the diamond to be less than 1 ppm, when Ti/Cu（1.6 wt%） is added in the FeNiCo catalyst.

关 键 词：high pressure and high temperature catalyst nitrogen getter type-Ⅱa large diamond 

分 类 号：TQ163[化学工程—高温制品工业]