Experimental соnfirmation of posibility of synthesis of diamond single crystals similar to natural
Т.А.Nachalnay, V.G.Маlogolovets, G.А.Podzyarey, S.А.Ivahknenko, О.А.Zanevskiy,
Institute for Superhard Materials of NAS of Ukraine, Kyiv, Ukraine
Institute of General & Inorganic Chemistry of NAS of Ukraine , Kyiv, Ukraine
The diamond crystals which has been brought up in nonconventional systems, as well as obtained by a method of a temperature gradient at halving on a seeding agent and synthesised from hydrocarbons, were studied by ESR and IR-spectroscopy methods.
It was founded that diamond crystals, in which impurity nitrogen is in nonparamagnetic centres A and which are peculiar to natural diamonds of 1а type are formed in conditions of a temperature gradient It was assumed that the formation of diamonds of Iа type in the natural geological conditions can occur analogically to the conditions of a temperature gradient synthesis methods.
The superhyperfine interaction of electrons of nitrogen impurity atoms noninteracting among themselves of with 13С (I=1/2) isotopes, located in the proximate surrounding, for the first time was stated on synthetic diamonds. Practically complete coincidence of constants of a hyperfine interaction (A|| = 57,2 Gs, and A^= 41,0 Gs) computed from an experimental spectrum, with dates, which one were obtained earlier on natural diamonds and on synthetic diamonds doped by an isotope 15N, was settled. It was revealed, that the entrance of nitrogen paramagnetic centers does not obey to the law of a random distribution in diamonds synthesised from hydrocarbons. The detected diversions was connected with the an initial carbon material. In hydrocarbons with amine-groups the nitrogen distributed not incidentally, but in a particular degree is ranked. Regulating of nitrogen atoms is maintained when they enter in crystals of synthesised diamond as an impurity. It is possible to suppose, that the conditions of diamonds formation of from hydrocarbons in some measure model the separate stages of natural diamonds growth.
The results obtained testify to possibility of synthesis of diamond crystals, which on the properties will be similar to natural ones.
The authors of this research is gratefully acknowledged for providing financial support by USTC, project 1622
Keywords: diamond, temperature gradient, nitrogen, hydrocarbons
The corresponding author:
Name: Tamara A. Nachalnaya
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