Effect of Ni2O3 on diamond crystal growth in an Fe–Ni–C system under high temperature and high pressure

CrystEngComm ◽  
2021 ◽  
Vol 23 (15) ◽  
pp. 2809-2815
Author(s):  
Peiyang Mu ◽  
Guangtong Zhou ◽  
Liangchao Chen ◽  
Zhuangfei Zhang ◽  
Yuewen Zhang ◽  
...  

In this paper, the oxygen-containing diamond large single crystals were successfully synthesized by adding Ni2O3 to the Fe–Ni–C system under HPHT. The oxygen affects the P–T conditions for diamond synthesis, and morphology of diamond.

2014 ◽  
Vol 42 ◽  
pp. 21-27 ◽  
Author(s):  
Shishuai Sun ◽  
Xiaopeng Jia ◽  
Bingmin Yan ◽  
Fangbiao Wang ◽  
Yadong Li ◽  
...  

2012 ◽  
Vol 727-728 ◽  
pp. 56-60
Author(s):  
Ana Lúcia Diegues Skury ◽  
Sérgio Neves Monteiro ◽  
Simone S.S. Oliveira

The development of technological processes for obtaining small size diamond powder is of industrial interest as basic products for roughing and finishing surfaces, like in the polishing of ornamental rocks. Therefore, this work investigates the influence of zinc, as a doping agent, in association with the graphite to diamond transformation, which occurs during high pressure and high temperature synthesis in the presence of Ni-Mn as a catalyst-solvent metallic alloy. Diamond synthesis was carried out at 4.7 GPa of pressure and 1300°C using a reactive mixture with 1:1 ratio of graphite and Ni-Mn alloy powders doped with up to 6% of Zn. The results indicated that the highest diamond yield was obtained for 0.5% while the lowest yield for 6% of Zn. Regardless the Zn content , the diamond crystal were produced with 212/150 μm of granulometry.


2008 ◽  
Vol 51 ◽  
pp. 141-147
Author(s):  
Bin Xu ◽  
Li Li ◽  
Mu Sen Li ◽  
Cai Gao ◽  
Ren Hong Guo

Despite many studies have been carried, there is no clear understanding of the growth mechanism involved in the high-pressure and high-temperature (HPHT) diamond synthesis with metal catalyst, especially the problem about carbon source. In this paper, the lattice constants of diamond, graphite and Fe3C at HPHT were calculated with the linear expansion coefficient and elastic constant. Then based on the empirical electron theory of solids and molecules (EET), the valence electron structures of them and their common crystal planes were calculated, and the boundary condition of electron movement in the Thomas-Fermi-Dirac theory modified by Cheng (TFDC) was applied to analyzing the electron density continuity of the interface. It was found that the relative electron density differences across graphite/diamond interfaces are great and discontinuous at the first order of approximation, while the relative electron density differences across Fe3C/diamond interfaces were continuous. The results show that the carbon atom cluster is easier to decompose from Fe3C than from graphite and to transform into diamond structure, so the carbon source for diamond crystal growth may come from the decomposition of Fe3C instead of graphite. Accordingly, the diamond growth mechanism was analyzed from the viewpoint of valence electron structure.


2002 ◽  
Vol 55 (6) ◽  
pp. 397-402 ◽  
Author(s):  
Long-Wei Yin ◽  
Mu-Sen Li ◽  
Dong-Sheng Sun ◽  
Feng-Zhao Li ◽  
Zhao-Yin Hao

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.


CrystEngComm ◽  
2020 ◽  
Vol 22 (44) ◽  
pp. 7601-7606
Author(s):  
Chunxiao Wang ◽  
Hong-an Ma ◽  
Liangchao Chen ◽  
Xinyuan Miao ◽  
Liang Zhao ◽  
...  

Here, a new type of supercharged cell assembly is proposed that can effectively reduce the oil pressure during high-pressure, high-temperature (HPHT) diamond synthesis.


2001 ◽  
Vol 72 (2) ◽  
pp. 1406 ◽  
Author(s):  
Teruya Tanaka ◽  
Junichi Kaneko ◽  
Daisuke Takeuchi ◽  
Hitoshi Sumiya ◽  
Masaki Katagiri ◽  
...  

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