Theoretical Study Group

Theoretical research group was created in 2011 to support the experiments are carried out in FSBSI TISNCM. At present time the theoretical group includes:



Ph.D., senior research scientist
Sorokin Pavel (CV)
phone number: +7 (499) 400-62-25 (416)
mobile phone: +7-916-474-66-64
e-mail.:
skype: pavel_b_sorokin


 

Ph.D., research scientist
Antipina Liubov (CV)
phone number: +7 (499) 400-62-25 (416)
mobile phone: +7-916-746-96-58
e-mail.:
skype: lyubov_antipina




Postgraduate student
Kvashnin Alexander (CV)
phone number: +7 (499) 400-62-25 (416)
mobile phone: +7-915-175-05-40
e-mail.:
skype: alexander.g.kvashnin

 

Postgraduate student
Kvashnina Yulia (CV)
phone number: +7 (499) 400-62-25 (416)
mobile phone: +7-965-361-64-35
e-mail.:

Research group engages a wide spectrum of problems in material science using quantum-chemical simulation methods.

THE MAIN DIRECTION OF RESERCH

  • The search for new superhard materials

    It is well known that diamond is the hardest crystal among all known materials. Superhard materials are used in various fields: microelectronics, engineering works, for sharpening clean surfaces for optical components, memory disks, drums for copy machines, for mechanical treatment of various solid metals, alloys and etc. Currently, the diamond anvils are used for the achieving ultrahigh pressure. Applying of new stronger and harder materials leads to increasing the opportunity of experiments to create ultrahigh pressures and synthesize new high pressure phases, to expand scientific knowledge, techniques and technologies.

    However, there are a number of cases where application of diamond is impossible or undesirable. For example, diamond can react with treated material at high temperature. Also diamond is rather expensive material.

    The search of new carbon materials which are stronger and harder than diamond is one of the most prospective developing areas of modern materials science. On the other hand, producing of a material with good hardness characteristics is important not only from a practical point of view but also for understanding the connection between the microscopic characteristics of the interatomic interactions and macroscopic properties of matter. It is very important to compare the experimental results with theoretical calculations. The result of the research groups from FSBSI TISNCM was a series of experimental papers [1,2], where a new superhard phase based on the fullerene C60 with hardness much higher than the diamond hardness called tisnumit was reported. This material was obtained at pressures and temperatures above than 13 GPa and 2100 K. Several possible structures were suggested to describe atomic structure but the exact atomic structure is still unknown. Quantum chemical and molecular dynamics methods could be useful in this problem. Quantum chemical programs allow us to make complex investigation of such object and predict properties and condition of its production (Figure 1).



    Figure 1. New predicted phase of carbon

  • The investigation of properties of diamond based nanostructures

    Ultrathin diamond films with nanometer thickness (Figure 2) are investigated using ab initio (first-principles) calculation methods. These materials have unique electronic and mechanical properties, so it is very important to study the phase transformation from multilayered graphene to ultrathin diamond films.



    Figure 2. Atomic structures of graphene, graphane and ultrathin diamond film diamane

  • The study of the properties of prospective nanomaterials in a field of hydrogen energetic

    Lack of efficient hydrogen storage material is one of the major problems towards successful use of hydrogen as green alternative fuel for vehicles. The US Department of Energy has set the hydrogen gravimetric capacity target of 6.5 wt% in the perspective materials for industrial usage. Because of its light weight and large surface area, carbon-based nanostructures are considered as most promising materials for the hydrogen storage. Carbon nanostructures decorated by transition and alkali metal atoms have shown high potential for hydrogen storage materials which was confirmed by number of theoretical and experimental studies. We have shown that such carbon materials as carbyne and graphane with bonded metal atoms (Figure 3) could be used as prospective material for hydrogen storage.





    Figure 3. A – carbyne with adsorbed atoms of calcium, B – graphane with adsorbed atoms of alkali metals


COMPUTATIONAL METHODS

The research methods used in our group are included different theoretical approaches: ab initio, semiempirical methods and classical potentials.

The electronic and mechanical properties of all investigated structures are determined using methods of density functional theory (DFT) implemented in such software packages as VASP, QuantumEspresso, SIESTA which allows to estimate a wide range of properties (mechanical, electronic, optical) of bulk and nanoscale materials. Also DFT method is widely used for calculation of phase diagrams (Figure 4). Using this method it is possible to estimate the values of phase transition pressure with good accuracy in a wide temperature range and allows to study the metastable phases which are not always easy to obtain in experiments.



Figure 4. Phase diagram for graphite-diamond transition obtained in experiment in comparison with simulation

Classical molecular dynamics method with empirical interatomic potentials implemented in such software packages as LAMMPS and GULP are used in our group. The main advantage of this approach is possibility to investigate materials consisted of hundreds and thousands of atoms with sufficient accuracy.

All calculations of simulation of carbon material properties are carrying out using high performance computing cluster T-Platform T-Blade 1.1.

 

Publications

2013

Articles in scientific journals:
  • P. B. Sorokin, L.A. Chernozatonskii. Semiconducting nanostructures based on graphene UFN – 2012 (in press).
  • Sakai S, Matsumoto Y., Ohtomo M., Entani S., Avramov P.V., Sorokin P.B., Naramoto H. High spin polarization at the Fe/C60 interface in the Fe-doped C60 film // Synthetic Metals 2012 (in press).

2012

Articles in scientific journals:
  • Chernozatonskii L.A., Mavrin B.N., Sorokin P.B., Determination of ultrathin diamond films by Raman spectroscopy // Physica Status Solidi B 2012. V.8. P. 1550-1554 (DOI: 10.1002/pssb.201147478, download pdf).
  • Determination of ultrathin diamond films by Raman spectroscopy / L.A. Chernozatonskii, B.N. Mavrin and P.B. Sorokin // Physica Status Solidi B – 2012 (в печати, DOI: 10.1103/PhysRevB.86.085435, download pdf).
  • Chernozatonskii L.A., Kvashnin D.G., Sorokin P.B., Kvashnin A.G., Brüning J.W. Strong, Influence of Graphane Island Configurations on the Electronic Properties of a Mixed Graphene/Graphane Superlattice // J. Phys. Chem. C 2012. V.116, №37. P. 20035-20039 (DOI: 10.1021/jp304596y, download pdf).
  • Avramov P.V., Fedorov D.G., Sorokin P.B., Sakai S., Entani S., Ohtomo M., Matsumoto Y., Naramoto H. Intrinsic Edge Asymmetry in Narrow Zigzag Hexagonal Heteroatomic Nanoribbons Causes their Subtle Uniform Curvature // J. Phys. Chem. Lett. 2012. V.3. P. 2003-2008 (DOI: 10.1021/jz300625t, download pdf).

Participations in conferences:
  • Kvashnin A. G., Sorokin P. B., Chernozatonskii L. A., Ultrathin diamond nanofilms as possible two-dimensional insulator: electronic and elastic properties, Abstracts of International conference “Towards Reality in Nanoscale Materials V” (TRNM V), Levi, Lapland, Finland, 20-22 February 2012, p. – 72.
  • Filicheva Yu. A., Kvashnin A. G., Sorokin P. B., Theoretical investigation of the diamond films with implanted oxygen atoms, Abstracts of International conference “Towards Reality in Nanoscale Materials V” (TRNM V), Levi, Lapland, Finland, 20-22 February 2012, p. – 62.
  • Yu. A. Filicheva, L. Yu. Antipina, A. G. Kvashnin, P. B. Sorokin, New superhard carbon modifications: structure and properties, Conference proceeding and abstracts of eighteenth Russia scientific conference of physicist and young scientists, Krasnoyarsk, Russia, 29 March – 5 April 2012, p.-641.
  • Filicheva Yu. A., Kvashnin A.G., Antipina L. Yu., Sorokin P. B., «New superhard carbon allotropes: elastic and electronic properties». The IV International Seminar on Nanosciences and Nanotechnologies, Ciudad de la Habana, Cuba, 17-19 September 2012.
  • Kvashnin A. G., Sorokin P. B., Chernozatonskii L.A., Particularities of phase transitions in ultrathin diamond films: theoretical study, Proceedings of XII Annual International Youth Conference "Biochemical Physics" IBCP RAS, Moscow, Russia, 29-31 October 2012.
  • A. G. Kvashnin, L. A. Chernozatonskii, T. P. Sorokina, P. B. Sorokin, Theoretical investigation of the properties of ultrathin diamond films, Proceedings of the Eighth International Conference on Carbon: fundamental problems of science, materials science, technology, Moscow, Troitsk, Russia, 25 - 28 September 2012.
  • Yu. A. Filicheva, A. G. Kvashnin, T. P. Sorokina, P. B. Sorokin, Structure and properties of new carbon allotropes, Proceedings of the Eighth International Conference on Carbon: fundamental problems of science, material science, technology, Moscow, Troitsk, Russia, 25 – 28 September 2012, p.-533.

2011

Articles in scientific journals:
  • Sorokin P. B., Singh A. K., Lee H., Antipina L. Yu. and Yakobson B.I. Calcium-Decorated Carbyne Networks as Hydrogen Storage Media // Nano Lett. – 2011. – V.11, №7. – PP: 2660–2665 (DOI: 10.1021/nl200721v, download pdf). See also on the topic: phys.org/news/2011-06-carbon-grapevine-hydrogen.html.
  • Chernozatonskii L. A., Sorokin P. B., Kuzubov A. A., Sorokin B. P., Kvashnin A. G., Kvasnin D. G. and Yakobson B. I. Influence of Size Effect on the Electronic and Elastic Properties of Diamond Films with Nanometer Thickness // J. Phys. Chem. C – 2011. – V.115, №1. – P.132-136, (DOI: 10.1103/PhysRevB.86.085435, download pdf).

Participation in conferences:
  • Sorokin P. B., Chernozatonskii L. A., Avramov P. V., Kvashnin A. G., Electronic and elastic properties of diamond films with nanometer thickness, Book of abstracts International conference “Advanced carbon nanostructures”, St Petersburg, Russia, July 4-8, 2011, p. – 182.
  • Chernozatonskii L. A., Artyukhov B. I., Biro L., Mark. G., Sorokin P. B., Kvashnin A. G., Kvashnin D. G., Yakobson B.I., Nanostructures based on H- (or F-) atom functionalized graphene elements for electronic and optic nanoengineering, Book of abstracts International conference “Advanced carbon nanostructures”, St Petersburg, Russia, July 4-8, 2011, p. – 26.
  • Ribas M. A., Singh A. K., Sorokin P. B., Yakobson B. I. Nanoroads and Quantum Dots on Fluorinated Graphene Abstracts of Joint International Conference, Book of abstracts International conference “Advanced carbon nanostructures”, St Petersburg, Russia, July 4-8, 2011, p. – 105.
  • Kvashnin A. G., Sorokin P.B., Investigation of the features of phase transitions in ultrathin diamonds, Abstracts of the conference of young scientists of the Ural region with international participation, Perm, Russia, October 6-7, 2011, p. – 144.