Growth Of Type IB Diamond Crystal With Multi-seed Under High Temperature And High Pressure By Temperature Gradient

Diamond is a kind of limit functional materials with a number of excellent property, due to its remarkable properties, diamond has been widely used in many fields such as industry, scientific research, national defence, medical treatment and etc... especialy for gem diamond, is indispensable for the development of functional materials for high technology At abroad, the gem diamond synthetic techniques have made a vast development, and the research tendency in this field is to make maximum and unlimited use of the outstanding properties of diamond, including entering the gem markets. While at present, because of its great commercial value, the information on diamond synthetic techniques is always kept secret. Our country just began the study of gem diamonds growth recent years. High level diamond synthetic techniques can surely promote the development of industry, scientific research, national defence, medical treatment and so on.When adopt temperature gradient to synthesize gem dimond,with reaction cell enlarging, regrown graphite and spontaneous nucleus will appear,all of these factors have effect on diamond crytal quality. In addition , growth time of large dimond crystal need long time,production efficiency is low,moreover the cost of growth diamond crystal is difficult to lower,it result in larger diamond crystal is difficult to realize mass production. Based on these factors ,this article take same research on synthesiztion of dimond crystal under high temperature and high pressure with multi-seed by temperature gradient using china-made cubic anvil apparatus.,in research same results were found as follow :1,By test the highest part of pyrophyllite, it has found that NaCl has a good property at keeping temperature, and its capability of heat preservation better than ZrO₂.At last, stability synthesise cavity is established .2,Polycrystal are often grown when take NiMnCo as solvent metal,and polycrystal have no relation with growth velocity,when measure temperature we found that fluctuate of temperature is the most important factor which rusult in polycrystal formation.it has found that polycrystal often appear in center of reaction cell,and sometimes it has relation with seed grit size.Hence,by change the seed position and the size of seed grit,polycrystal phenomenon is alleviated .3,With content of Fe increasing in FeNiMnCo solvent metal, the probility of grown polycrystal decline, crystal quality is improved every single crystal growth velocity is as high as 1.88mg/hour,however,growth character changed from suiting {100} face for growth to {111} face.4,In FeNiCu catalyst system,due to the electronic structure of Cu in a stable electron configuration, its electronic in 3 d shell are difficult to share with other element , Cu is very difficult to...