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
abstract
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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