Research area:
Lattice Dynamics, phonons and
other quasiparticle excitations in solids:
 Vibrational characteristics of crystals with complex
defects;
 Dynamics of complex crystal lattices, strongly
anisotropic crystal structures, and
quasilowdimensional lattices.
 Quasiparticle spectra of nanosystems.
Main achievements:
 Microscopic calculations on the atomic dynamics of
the real crystal structures (ideal and with defects)
were made. New method for the localized states
description based on Jmatrix was suggested.
 Investigation of localization and propagation of
vibrations in heterogeneous crystals and disordered
solid solutions
 Creation of calculation models for investigation of
electron and phonon spectra of graphene based
structures.
Main Publications:
 S. Feodosyev, I. Gospodarev, V. Grishaev, A. Kosevich,
O. Kotlyar, E. Syrkin, Phonon Spectra and Discrete
Oscillatory Levels in Crystal Superlattices of
Deuterium and HydrogenPalladium Solid Solutions, J. of
Low Tem. Phys. 139, 665, 2005.
 A.V. Kotlyar and S.B. Feodosyev, Local oscillations
in crystal lattices with a simply connected region of
the quasicontinuonsphonon spectrum, Low Temperature
Physics, 32, No 3, 256, 2006.
 I.A. Gospodarev, V.I. Grishaev, O.V. Kotlyar, K.V.
Kravchenko, E.V. Manzhelii, E.S. Syrkin, and S.B. Feodosyev,
Ioffe–Regel crossover and boson peaks in disordered
solid solutions and similar peculiarities in
heterogeneous crystal structures
Low Temperature Physics, 34, No 8, 655, 2008.
 A. Kosevich, I. Gospodarev, V. Grishaev, A. Kotlyar,
V. Kruglov, E. Manzhelii, E. Syrkin, S. Feodosyev,
Specific Features of the Transformation of Local Levels
into an Impurity Band of Ag_{1p}Al_{p}
Disordered Solid Solutions, J. Exp. Theor. Phys. 105, 4,
2007
 A Feher,
E. Syrkin, I. Gospodarev, E. Manzhelii, A. Kotlyar, K. Kravchenko,
The Features of Low Frequency Atomic Vibrations and
Propagation of Acoustic Waves in Heterogeneous Systems,
in: “Waves in Fluids and Solids” (ed. R.P. Vila)
“InTex” Open Access Publisher,
ISBN 9789533072463 Croatia, 2011.
 I. Gospodarev, O.V. Kotlyar, K.V Kravchenko, E.V. Manzhelii,
E.S Syrkin, A.V.Yeremenko, I.K. Galetich, Low
Temperature Peculiarities of QuasiParticle Spectra of
Disordered Solid Solutions, in: “Contemporary Problems
of Mathematics, Mechanics and Computer Sciences” (eds. N.N. Kizilova,
G.N. Zholtkevich) PRB Virovec’,ISBN 9789662579925
Ukraine, 2011
 A.Feher, I.Gospodarev, O.Kotlyar, K.Kravchenko,
E.Manzhelii, E.Syrkin, S.Feodosyev Impurity levels in
the electron spectra of graphene, Superlattices and
Microstructures, 53, 55, 2013
