Research area: Lattice Dynamics, phonons and other quasi-particle excitations in solids:

• Atomic dynamics of multilayered crystals and crystals with complex defect structures;
• Atomic dynamics of boundary (surface, edge and apex) atoms;
• Computer modeling of complex crystal structures and disordered systems.

The main achievements:

• Typical distinctive features of phonon spectra of the semibounded strongly anisotropic crystals and thin layers of these compounds were studied (in collaboration with E. S. Syrkin); there was determined the dependence of the vibration thermodynamic characteristics of these systems upon the mentioned above features:
• Microscopic calculations of the vibration characteristics of crystal structures of the specified either ideal compounds or those having point and extended defects were made;
• There were built a number of calculating models to study the phonon spectra and vibration characteristics of crystals with complex defects, multilayered structures of the HTSC type, nanoclusters, microcontacts, etc. where the influence of the crystal atomic order regularity was weakened.
• Calculation of phonon spectra of heterogeneous crystals and disordered solid solutions
• Calculation of electron and phonon spectra of graphite and carbonic thin films.

Main Publications:

1. I.A.Gospodarev, S.B.Feodosyev, A.P.Isakina, A.I.Prokhvatilov, E.S.Syrkin, Effect of the Crystalline Structure Anisotropy of the High Temperature Superconductor Bi2Sr2CaCu2Ox on its Thermal Expansion ФНТ, 16, 673 (1990).
2. S.B.Feodosyev, I.A.Gospodarev, E.S.Syrkin, Anomalies of Linear Expansion Coefficient in Highly Anisotropic Crystals at Low Temperature, Phys, Stat. Sol (b), 150, K19, 1988.
3. S.B. Feodosyev, I.A. Gospodarev, A.M. Kosevich, E.S. Syrkin, Quasi-Low-Dimensional Effects in Vibrational Characteristics of 3D-Crystals, Phys. Low Dim. Str., 10/11, 209, 1995.
4. I.A. Gospodarev, A.V. Grishaev, E.S. Syrkin, S.B. Feodosyev, Local Vibrations of FCC-Crystals with Two Parametric Substitution Impurities, Phys. Solid State, 42, N12, 2000.
5. A.M. Kosevich, A. Mayer, S.B. Feodosyev, I.A. Gospodarev, V.I. Grishaev, E.S. Syrkin, Atom Dynamics of Micro-Clusters on Atomically Smooth Surfaces, Superlattices and Microstructures, 27, No 1, 7, 2000.
6. S.B. Feodosyev, I.A. Gospodarev, M.A. Strzhemechny, R.J. Hemley, Phonon Assisted Ortho- Para Conversion in Solid H₂ Under Pressure, Physica B: Physics of Condensed Matter, 300, 186, 2001.
7. E.T. Verkhovtseva, I.A. Gospodarev, A.V. Grishaev, S.I. Kovalenko, D.D. Solnyshkin, E.S. Syrkin, S.B. Feodosyev, Atom Dynamics and the Problem of the Structural Stability of Free Clusters of Solidified Inert Gases, Low Temperature Physics, 29, No 5, 386, 2003.
8. 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.
9. I.A. Gospodarev, K.V. Kravchenko, E.S. Syrkin and S.B. Feodos’ev Quasi-two-dimensional features in the phonon spectrum of graphite Low Temp. Phys. 35, No 7 589, 2009.
10. A. Feher, I.A. Gospodarev, V.I. Grishaev, K.V. Kravchenko, E.V. Manzheliĭ, E.S. Syrkin and S.B. Feodos’ev, Effect of defects on the quasiparticle spectra of graphite and graphene, Low Temp. Phys. 35, No 8, 679, 200.
11. I.K. Galetich, I.A. Gospodarev, V.I. Grishaev, A.V. Eremenko, K.V. Kravchenko, , V.A. Sirenko, S.B. Feodosyev, Vibrational characteristics of the niobium dichalcogenide. Bulk samples and nanofilms, Superlattices and Microstructures, 45, No 6, 564, 2009
12. I.A. Gospodarev, V.V. Eremenko, K.V. Kravchenko, V.A. Sirenko, E.S. Syrkin and S.B. Feodos’ev Vibrational characteristics of niobium diselenide and graphite nanofilms Low Temp. Phys. 36, No 4, 344 2010.
13. Alexander Feher, Eugen Syrkin, Sergey Feodosyev, Igor Gospodarev and Kirill Kravchenko Quasi-Particle Spectra on Substrate and Embedded Graphene Monolayers, in: “Physics and Application of Graphene – Theo-ry” (ed. S. Mikhailov) “InTex” Open Access Publisher, ISBN 978-953-307-996-7 Croatia, 2010.
14. A Feher, E. Syrkin, I. Gospodarev, E. Manzhelii, A. Kotlyar, K. Kravchenko, The Features of Low Frequency Atomic Vibrations and Propaga-tion of Acoustic Waves in Hete-rogeneous Systems, in: “Waves in Fluids and Solids” (ed. R.P. Vila) “InTex” Open Access Publisher, ISBN 978-953-307-246-3 Croatia, 2011.
15. Gospodarev, O.V. Kotlyar, K.V Kravchenko, E.V. Manzhelii, E.S Syrkin, A.V.Yeremenko, I.K. Galetich, Low Temperature Peculiarities of Quasi-Particle Spectra of Disordered Solid Solutions, in: “Contemporary Problems of Mathematics, Mechanics and Computer Sciences” (eds. N.N. Kizilova, G.N. Zholtkevich) PRB Virovec’,ISBN 978-966-2579-92-5 Ukraine, 2011
16. 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
17. I.A. Gospodarev, A.V. Eremenko, K.V. Kravchenko, A.F. Sirenko, V.A. Sirenko, E. S. Syrkin, S.B. Feodosyev, and Yu. A. Shabakaeva, Distinctive Features of Thermal Expansion of Niobium Diselenide, Physics of the Solid State, 55 No. 4, 825, 2013