“Mekhanobr Engineering” Company:

V. V. Zuev, Leading Researcher, Doctor of Geological and Mineralogical Sciences, e-mail: office@mekhanobr.spb.ru

Searching of new super hard materials includes investigation of the subsurface Earth areas substances nature (mantle and core), which (as it is now became clear) are considered to be the natural chemical reactors, forming substances with extreme physical properties serving as prototypes (analogues) of corresponding artificial compounds. Hardness, temperature of melting and many other properties of such substances can be predicted by the author`s formulas.

Majority of scientists consider inner core substance to have (Fe_0,9Ni_0,1) composition and body centered cubic (bbc) structure with eightfold coordination of atoms. According to our theoretical prediction such substance reveal valency 8 of metals, has parameter a_o = 2,47 A of cubic lattice, very strong covalent bonds and hardness more than diamond has.

Except compounds α-Fe(VIII) and α-Ni(VIII), some another hypothetical compounds are recommended as super hard materials — Fe(VIII)C(IV)₂, Ni(VIII)C(IV)₂ and Fe(VI)N(V)₂, having fluorite type structure (CaF₂). All these compounds are characterized by very high values of EV, kJ/cm³ (energy density — energy bonds quantity per volume unit) and of hardness HM, which exceed diamond`s corresponding values of EV and HM.

The real possibility of existing and artificial producing of new super hard materials was demonstrated in 2007, when a group of foreign scientists synthesized (at corresponding P-T conditions) substance of the inner core of the Earth with parameter a_o = 2,49 A, close to above predicted in 1997.

1. Povarennykh A. S. Tverdost mineralov (Mineral hardness). Kiev, 1963, 304 p.

2. Sobolev E. V. Tverzhe almaza (Harder than diamond). Novosibirsk, 1989,192 p.

3. Bradley D. New Scientist. 1993, Vol. 137, No. 1865, pp. 22–23.

4. Bradley D. New Scientist. 1995, Vol. 145, No. 1967, pp. 19.

5. Guo Y., Goddard W. Chem. Phys. Letters. 1995, Vol. 327, pp. 72–76.

6. Cahn R. W. Monthly Nature. 1996, Vol. 4, No. 3(39), pp. 32–33.

7. Zuev V. V. Obogashchenie Rud — Mineral Processing. 1997, No. 1, pp. 30–34.

8. Zuev V. V. Konstitutsiya, svoystva mineralov i stroenie Zemli (Mineral Constitution, Mineral Behavior and Earth Structure). St. Petersburg, 2005, 402 p.

9. Ross M., Young D. A., Grover R. Journal of Geophysical Research. 1990, Vol. 95, No. B13, pp. 21713–21716.

10. Matsui M., Anderson O. L. Physics of the Earth and Planetary Interiors. 1997, Vol. 103, pp. 55–62.

11. Belonoshko A. B., Ahuja R., Johansson B. Nature. 2003, Vol. 424, pp. 1032–1034.

12. Dubrovinsky L., Dubrovinskaia N., Narygina O. et al. Science. 2007, Vol. 316, pp. 1880–1883.

13. Zuev V. V. Energoplotnost, svoystva mineralov i energeticheskoe stroenie Zemli (Energy density, mineral behavior and energetic Earth structure). St. Petersburg, 1995,128 p.

14. Spravochnik po geokhimii. Pod red. Voytkevicha G. V., Kokina A. V., Miroshnikova A. E., Prokhorova V. G. (Geochemistry reference book. Edited by Voytkevich G. V., Kokin A. V., Miroshnikov A. E., Prokhorov V. G.). Moscow, 1990, 480 p.

15. Stixrude L., Brown J. M. Reviews in mineralogy. 1998, Vol. 37, pp. 261–282.

16. Poling L. Obshchaya khimiya (General chemistry). Moscow, 1974, 846 p.