The Faculty of Physics

Ruslan V. Vovk

    Academician of the National Academy of Sciences of Ukraine
    Academician of the TAU
    Honored Professor of V. N. Karazin Kharkiv National University
    Holder of the Order of Merit of the 3rd degree

    The Faculty of Physics,
    V. N. Karazin Kharkiv National University,
    4 Svobody Square, Kharkov 61022;
    Е-mail: r.v.vovk@karazin.ua

Education and academic qualifications
Appointment:

2024

 Academician of the National Academy of Sciences of Ukraine

2021

Corresponding Member of the National Academy of Sciences of Ukraine

2018

Honored Professor of the V.N. Karazin KhNU

2016

Academician of TAU

2013

Corresponding member of TAU

2012

Professor of the Department of Low Temperature Physics

2010

Professor of UkrSURT

2008

Professor of the Department of Low Temperature Physics

2008

Doctor of Physical and Mathematical Sciences, B.I. Verkin Institute of Low Temperature Physics and Technology of the NAS of Ukraine. Thesis title: "Dynamics of quasiparticle subsystems with different energy spectra in isotropic and anisotropic condensed media"

2006

Associate Professor at the Department of Physics, UkrSURT

2002-2004

PhD group "Quantum Liquids" of the University of Exeter (United Kingdom)

2002

Senior Research Fellow in the specialty 01.04.07 – Solid State Physics

2000

Associate Professor of the Department of Physics of the Ukrainian State Technical University and the Department of Physics and Technology of the V.N. Karazin National University of Kherson

1998

Candidate of Physical and Mathematical Sciences (PhD) in Superconductivity Physics, B.I. Verkin Institute of Low Temperature Physics and Technology, NAS of Ukraine. Dissertation title: "Structural Relaxation and the Influence of Point and Planar Defects on Vortex Pinning in YBaCuO Single Crystals"

1990

He received his master's degree in physics from Kharkiv State University.

    Since 1990, he has been working at the Department of Low Temperature Physics of V.N. Karazin Kharkiv National University, where he has gone all the way from engineer to professor:

  • 1990-1994 – engineer;
  • 1994-1997 – junior research associate;
  • 1997-1999 – Researcher;
  • 1999-2008 – Senior Researcher;
  • from 2008 to the present - professor of two departments - the Department of Low Temperature Physics and the Department of Physics of the UkrSURT;
  • from 2010 to 2012, he headed the Problematic Research Laboratory (PRL) of the Department of Low Temperature Physics;
  • From 2012 to 2016, he headed the Department of Low Temperature Physics;
  • from 2013 to the present - Dean of the Faculty of Physics.

    Since 2000, he has been working part-time at the Ukrainian State University of Railway Transport (UkrSURT). In 2006, he created the Department of General Technical Disciplines at UkrSURT, which he headed until 2008. From 2008 to February 2018, he was part-time head of the Department of Physics at UkrSURT, and from 2018 to the present, he is a professor of this department.

Awards

  • Two-time laureate of the personal scholarship of the Cabinet of Ministers of Ukraine for young scientists (1994-1996 and 1998-2000).
  • Gold Medal of the European Scientific Community (as part of the "Quantum Liquids" group of the Royal Academician Prof. A.F.J. Wiatt) – 2004.
  • 4-time Grand Prix laureate of the V.N. Karazin Prize - 2008, 2011, 2015, 2019.
  • Medal "For Promoting the Development of the Southwestern Railway" - Order No. NOK-514 dated November 12, 2011.
  • Gratitude of the Presidium of the NAS of Ukraine – 2015
  • Gratitude of the Transport Committee of the Verkhovna Rada of Ukraine - 2015
  • Gratitude of the Ministry of Education and Science of Ukraine – 2015
  • Scholarship of the Kharkiv Regional State Administration in the field of science (K.D. Synelnikov scholarship) in the nomination "Outstanding Scientist" - April 2016.
  • V.N. Karazin Medal - April 26, 2016
  • Silver Badge of the Southern Railway - 2017
  • Honorary Certificate of the Presidium of the NAS of Ukraine – May 16, 2018.
  • Honorary title "Honored Professor of V.N. Karazin Kharkiv National University" – December 17, 2018.
  • Jubilee Certificate of Honor of the Presidium of the NAS of Ukraine – Resolution No. 43 of January 31, 2018 of the Presidium of the NAS of Ukraine on the Jubilee Certificate of Honor.
  • Honorary Certificate of the Ministry of Education and Science of Ukraine - 2019
  • Medal of the International Academy of Rating Technologies and Sociology (MARTIS) "Golden Fortune" - "People's Honor to Ukrainian Scientists. 1918 - 2018" - (January 2019, medal No. 189).
  • L.V. Shubnikov Prize of the NAS of Ukraine – Resolution No. 40 of the Presidium of the NAS of Ukraine dated February 13, 2019.
  • Badge "Excellent in Education" of the Ministry of Education and Science of Ukraine No. 309, Order 399-k dated 02.11.2020.
  • Order of Merit, 3rd degree - awarded by Decree of the President of Ukraine dated January 25, 2020 No. 22/2020. OK Series No. 050787. Badge of the Order No. 15101.
  • NASU B.I. Verkin Prize – Resolution of the Presidium of NASU dated 06.03.2024.

Participation in international programs

    Participant of two NATO special projects in 1995-1999. From 2002 to 2004, he underwent a research internship at the University of Exeter (Great Britain) in the world-famous Quantum Liquids group under the leadership of Royal Academician Professor A.F.J. Wiatt. On the initiative and direct participation of Professor R.V. Vovk, the V.N. Karazin Kharkiv National University received registration in the register of leading classical universities in Europe (Validaton of Kharkiv National University PIC 986260984), which allows the university to participate in EU-wide programs for academic exchange and scientific cooperation. For the first time, the idea of ​​modulating spin waves in ferromagnets by the Abrikosovsky vortex subsystem, and vice versa - regulating the dynamics of magnetic flux in superconductors by a “magnon coat” was proposed in 2014. by a group of British-Ukrainian scientists within the framework of the project “NoWaFen” (“Novel Wave Phenomena in Magnetic Micro- and Nanostructures”) – Grant agreement No. PIRSES-GA-2009-247556, headed by Professor R.V. Vovk from the Ukrainian side. Among the first in Ukraine, the V.N. Karazin Kharkiv National University was awarded a grant in the International Research Academic Exchange Program (IRSES) Horizon 20-20 within the framework of the project “MaglC” (Grant Agreement number 644348 – MaglC-H2020-MSCA-RISE-2014), the coordinator of which from the Kharkiv region was Prof. R.V. Vovk. On the initiative and direct participation of R.V. Vovk, the “Agreement on Double Degrees between the P.J. Shafarik University in Košice (Slovak Republic) and the V.P. Kharkiv National University” was concluded. Karazin (Ukraine)". At the initiative of Professor R.V. Vovka, a grant was received under the Erasmus+ program in 2019 jointly with the Pavlo-József Šafárik University.
    R.V. Vovka is a member of the Scientific Committee from Ukraine in the European Organization for Cooperation in Science and Technology (COST – European Cooperation in Science & Technology) (since 2017). Unanimously re-elected in 2021.

Community activities
  • Member of two Specialized Academic Councils for the Defense of Doctoral Dissertations;
  • Member of the Academic Council of the V.N. Karazin KhNU and the Academic Council of the UkrSUZT.
  • Chairman of the Academic Council of the Faculty of Physics of the V.N. Karazin KhNU
  • Editor-in-chief of the journal “Bulletin of Kharkiv National University, series “Physics”;
  • Editor-in-chief of the Collection of Scientific Papers of UkrSUZT;
  • Member of the editorial board of the journal "Low Temperature Physics";
  • Member of the editorial board of the journal "Eastern European Journal of Advanced Technologies";
  • Chairman of the organizing committee of the international conference "Physical Phenomena in Solids", which takes place once every two years;
  • Member of the Scientific Council on the problem of "Low-temperature physics and cryogenic technology", section "Physics of quantum liquids and crystals" of the National Academy of Sciences of Ukraine (since 2014);
  • Member of the Scientific Committee from Ukraine in the European Organization for Cooperation in Science and Technology (COST – European Cooperation in Science & Technology) (since 2017);
  • Member of the Expert Council of the Ministry of Education and Science of Ukraine in the field of "General Physics".
  • Member of the State Prize Committee in Physics.
  • Since 2024, member of the National Committee of the National Council of Ukraine for the Development of Science and Technology.

Scientific and pedagogical activities

    R.V. Vovk has been working as a teacher since 2000. During this period, he taught a number of author's special courses in the state language: "Fundamentals of Quantum Liquid Physics", "Introduction to Superconductivity", physics courses for students of technical specialties of universities, a course in medical and biological physics, and the course "Cryogenic Materials Science" in English.
    Under his leadership, special workshops on the study of the properties of solids at low temperatures were modernized, and a modern physics workshop was created for the course "Medical Physics". R.V. Vovk created an interdisciplinary laboratory together with the Semiconductors lab. (Svetlovodsk) and opened a number of branches of the KFNT in academic institutes (in particular, the B.I. Verkin Institute of Physics and Technology, the Monocrystal Research Institute, the O.Ya. Usykov Institute of Physics and Technology, etc.).
    Professor R.V. Vovk is a well-known specialist in the field of high-pressure physics and extreme states of matter. The main areas of his scientific activity are superconductivity (including high-temperature) and superfluidity, including under conditions of extreme external actions (high pressure, low and ultralow temperatures, ionizing radiation, high magnetic fields).
From 2002 to 2004, he underwent a scientific internship at the University of Exeter (Great Britain) in the world-famous group "Quantum Liquids" under the leadership of Royal Academician Professor A.F.J. Wiatt. During his internship, he managed to develop the scientific foundations of a new direction in low and ultralow temperature physics - the dynamics of subsystems of quasiparticle excitations under conditions of structural and kinematic anisotropy. For the first time in the world, he developed an experimental technology for the separate detection of high- and low-energy phonons in superfluid quantum liquids; established the regularities of the generation of "hot" h-phonons; first proposed and implemented a method for studying the processes of interaction of several independent phonon beams during their collision in superfluid 4He (including at elevated pressure); discovered the phenomenon of "hot line" generation at ultralow temperatures.
After completing his internship in the UK, R.V. Vovk continued his scientific research on superconductivity, in particular, he was the first to discover the phenomenon of upward diffusion in HTNP materials under the action of high pressure, studied the effect of high hydrostatic pressure on pseudogap and fluctuation anomalies, as well as incoherent electrical transport in non-stoichiometric cuprates.
    R.V. Vovk is the founder of one of the most promising new directions in modern solid-state physics – the physics of fluxon-magnon heterostructures. For the first time, the idea of ​​modulating spin waves in ferromagnets by the subsystem of Abrikosovsky vortices, and vice versa – regulating the dynamics of the magnetic flux in superconductors by a “magnon coat” was proposed in 2014 by a group of British-Ukrainian scientists within the framework of the project “NoWaFen” (“Novel wave phenomena in magnetic micro- and nanostructures”) – Grant agreement No. PIRSES-GA-2009-247556, the author of which from the Ukrainian side was Professor R.V. Vovk. The idea received its experimental embodiment in Ukrainian-German experiments in the study of unique metamaterials with a given pinning potential in the form of a "washboard", created by nanomilling of samples in a scanning tunneling microscope. Based on the results of the experiments, a series of pioneering works was published in the leading publishing house Nature, co-authored by Professor R.V. Vovk. The result of these studies was the discovery of a magnon superconducting crystal. The corresponding report, which was presented by Professor R.V. Vovk with co-authors at the international conference on magnetism, which took place in August 2017 at St. Magdalene College at the University of Oxford (Great Britain), caused a great resonance among the world scientific community. In the future, the results obtained will form the basis for the development of new multifunctional materials with given parameters of electric transport, providing components for the manufacture and testing of memory elements based on new physical principles; in the creation of quantum computers, ultrasensitive reading elements and ultrafast communication lines.
    R.V. Vovk is known for his outstanding personal achievements in establishing fruitful scientific contacts with many leading scientific institutions in Europe and America. In his scientific work, Professor R.V. Vovk constantly collaborates with scientific teams of such leading world scientific centers as Oxford, Cambridge, Imperial College, National Laboratory, Coventry, Universities of Exeter and St. Andrews (Great Britain), Goethe University (Frankfurt am Main, Germany), Institute of Solid State Physics "Demokritos" (Athens, Greece), Institute Don Alfonso III (Portugal), University of New Brunswick (Canada), University P.J. Šafarík (Košice, Slovakia), University A. Mickiewicz (Poznan, Poland), with whom he has a number of joint publications.
R.V. Vovk was the head of 19 national research works. He is the author of 3 monographs, 15 educational and teaching-methodical manuals, 7 of them with the seal of the Ministry of Education and Science; more than 550 scientific works published in rated Ukrainian and foreign scientific publications (of which 367 are reflected in the scientific metric databases Scopus and Web of Sciences, 7 articles are published in the Nature publishing house, which is taken into account when determining international rankings of universities in the world): the author of more than 30 patents for inventions.
    As of January 2025, the h-index of Professor R.V. Vovk is 50, according to which he is among the 50 best scientists of Ukraine according to the V.I. Vernadsky Institute.
    R.V. Vovk, as Dean of the Faculty of Physics, actively involves students of the faculty in scientific work, ensuring their participation in the work of branches of the departments of low-temperature physics and general physics at the B.I. Verkin Institute of Physics and Technology of the National Academy of Sciences and international programs (Germany, Great Britain, Spain, Slovakia, Belgium, Poland, Russia (Joint Center for Nuclear Research, Dubna), etc.). In 2018, on the initiative and with the direct participation of R.V. Vovk, the “Agreement on Double Diplomas between the P.J. Shafarik University in Košice (Slovak Republic) and the V.N. Karazin Kharkiv National University (Ukraine)” was concluded.

Science school

    After returning from Great Britain, R.V. Vovk founded a scientific school of high-pressure physics and extreme states of matter, which has been fruitfully working at the Physics Faculty of the V.N. Karazin KhNU to the present day. The main areas of scientific research of this school are:
  • study of the topological features of the Fermi surface of transition metal dichalcogenides under the action of high uniaxial pressure (up to 8 kbar);
  • study of the effect of high hydrostatic pressure (up to 25 kbar) on pseudogap and fluctuation anomalies, as well as incoherent electrical transport in non-stoichiometric HTNP cuprates;
  • ultrahigh pressure research (from 300 kbar to 1.5 Gbar) on topological phase transitions in new multifunctional materials;
  • the use of high pressure in the synthesis of new nanocomposite materials by the electroconsolidation method;
  • research into extreme states of matter, in particular superconductivity and superfluidity at low and ultralow temperatures, as well as the influence of structural and kinematic anisotropy on the evolution of quasiparticle subsystems in quantum environments of various morphologies under the action of extreme external factors.

    Currently, the scientific school of high-pressure physics and extreme states of matter headed by Professor R.V. Vovk has about 100 people. Under his direct supervision, 5 candidate, 1 PhD and 1 doctoral theses were defended on this topic, as well as more than 80 master's and bachelor's theses. 5 candidate and 3 doctoral theses are at various stages of preparation for defense.
R.V. Vovk's original developments in the field of high-pressure processing in the synthesis of advanced functional materials are protected by a number of Ukrainian patents for inventions and have been repeatedly implemented in various sectors of the national economy.
The scientific school headed by Prof. R.V. Vovk works in close collaboration with numerous leading scientific institutions in Europe and North America. In particular, in his scientific work, Prof. R.V. Vovk with its employees, it fruitfully cooperates with scientific teams of such leading world scientific centers as Oxford, Cambridge, Imperial College, National Laboratory, Coventry, Universities of Exeter and St. Andrews (Great Britain), Max Planck Institute, Goethe University (Frankfurt am Main, Germany), University of Vienna (Austria), Institute of Solid State Physics "Demokritos" (Athens, Greece), University of Lisbon, Don Alfonso III Institute (Portugal), University of Maine (USA), University of New Brunswick (Canada), P.J. Šafarík University (Košice, Slovakia), A. Mickiewicz University (Poznan, Poland).

Publications:

International peer-reviewed publications (works published after 1993):

  • More than 370 publications in leading international journals, participation in more than 150 international conferences. Total number of publications more than 550.
  • h-index (Scopus) = 50

1. Kh.B.Chachka, M.A.Obolenskii, D.D.Balla, V.I.Beletskii, and R.V.Vovk / Effect of hydrostatic pressure on the critical temperature of niobium diselenide with tin impurity.// Low Temp. Phys.-1993.-19(4).-p.317-318.
2. M.A.Obolenskii, A.V.Bondarenko, V.A.Shklovskij, Mohamed El-Saadawy, R.V.Vovk, A.V.Samojlov, D.Niarchos, M.Pissas, G.Kallias, A.G.Sivakov / Superconducting parameters and vortex dynamics in aluminium-doped YBaCuO single crystals containing unidirectional twins. // Low Temp. Phys.-1995.-21(12). -p.917-922.
3. D.D.Balla, A.V.Bondarenko, R.V.Vovk, M.A.Obolenskii, and A.A.Prodan. // Effect of hydrostatic pressure on the resistance and critical temperature of YBa2Cu3O7-δ single crystals. / Low Temp. Phys.-1997.-23(10).-p.777-781.
4. A.V.Bondarenko, V.A.Shklovskij, M.A.Obolenskii, R.V.Vovk, and A.A.Prodan. /Resistivity investigations of plastic vortex creep in YBa2Cu3O6.95 crystals. // Phys.Rev.B.-1998, N1 -p.2445-2447.
5. A.V.Bondarenko, A.A.Prodan, M.A.Obolenskii, R.V.Vovk, D.Niarchos, M.Pissas, G.Kallias, T.R.Arouri.// Current-voltage characteristics in the vicinity of the fishtail peak in YBa2Cu3O6.95 single crystals. / Physica C.-1999, 655-657. -317-318.
6. M.A.Obolenskii, A.V.Bondarenko, A.A.Prodan, R.V.Vovk, M.G.Revyakina, T.R.Arouri. / Anisotropy of the vortex creep in a YBa2Cu3O7-δ single crystal with unidirectional twin boundaries. // Low Temperature Physics. -27, N3.-2001. -P.201-215.
7. R.V.Vovk, C.D.H.Williams and A.F.G.Wyatt. / Angular distribution of a pulse of low energy phonons in liquid 4He.// Phys. Rev. B 68, 134508 (2003)
8. R.V.Vovk, C.D.H.Williams and A.F.G.Wyatt. /Iterations between Sheets of Phonons in Liquid He-4. // Phys. Rev. Lett. 91, 235302 (2003).
9. R.V.Vovk, C.D.H.Williams and A.F.G.Wyatt. /High-energy phonon pulses in liquid 4He.// Phys.Rev.B69.144524 (2004).
10. I.N. Adamenko, K.E. Nemchenko, V.A. Slipko, R.V.Vovk, C.D.H. Williams and A.F.G. Wyatt / Spatial evolution of pulses of low-energy phonons in liquid 4He. // Journal of Molecular Liquids, Volume 120, Issues 1-3, June 2005, Pages 163-165
11. D.H.S.Smith, R.V.Vovk, C.D.H.Williams and A.F.G.Wyatt / Pressure dependence of phonon interactions in Liquid 4He.// Phys.Rev.B 72, 054506 (2005).
12. D.H.S.Smith, R.V.Vovk, C.D.H.Williams and A.F.G.Wyatt./ Interactions between phonon sheets in superfluid helium.// New Journal of Physics 8, 128 (2006)
13. R.V.Vovk, M.A.Obolenskii, A.A.Zavgorodniy, A.V.Bondarenko, I.L.Goulatis, A.I.Chroneos./ Excess conductivity and pseudo-gap state in YBCO single crystals slightly doped with Al and Pr// J Mater Sci: Mater in Electron 18, p.811-815 (2007).
14. R.V.Vovk, M.A.Obolenskii, A.A.Zavgorodniy, A.V.Bondarenko, I.L.Goulatis, A.V.Samoilov, A.I.Chroneos./ Influence of high pressure on the para-conductivity and the charge transfer in the ab-plane of YBa2Cu3O7-δ single crystals.// J. Alloys and Compounds 453, P. 69-74 (2008).
15. R.V.Vovk, M.A.Obolenskii, A.A.Zavgorodniy, A.V.Bondarenko, I.L.Goulatis, A.V.Samoilov, A.I.Chroneos, V.M. Pinto Simoes./ Transport anisotropy and pseudo-gap state in oxygen deficient ReBa2Cu3O7-δ (Re=Y, Но) single crystals.// J. Alloys and Compaunds 464, P. 58-66 (2008).
16. R.V. Vovk, M.A. Obolenskii, A.A. Zavgorodniy, I.L. Goulatis, V.I. Beletskiy./ Structural relaxation, metal-to-insulator transition and pseudo-gap in oxygen deficient НоBa2Cu3O7-δ single crystals.// Physica C. DOI: 10.1016/j.physc.2009.01.011 Physica C. –V.469. – P. 203-206.(2009).
17. R.V. Vovk, M.A. Obolenskiy, A.A. Zavgorodniy, D.A. Lotnyk, K.A. Kotvitskaya / Temperature dependence of the pseudogap in aluminum- and praseodymium-doped YBa2Cu3O7-δ single crystals // Physica B 404 (2009) p. 3516-3518.
18. A. Chroneos, R.V. Vovk, I.L. Goulatis, and L.I. Goulatis. / Oxygen transport in perovskite oxides: А brief review. // J. Alloys and Compounds. -494. -2010. –P.190-195.
19. O. Biletska, Y. Biletskiy, H. Li and R. Vovk / A semantic approach to expert system for e-Assessment of credentials and competencies // Expert Systems with Applications Volume 37, Issue 10, October 2010, Pages 7003-7014, doi:10.1016/j.eswa.2010.03.018.
20. R. V. Vovk, Z. F. Nazyrov, M. A. Obolenskii, I. L. Goulatis, A. Chroneos, V.M. Pinto Simoes / Effect of small oxygen deficiency on the para-coherent transition and 2D-3D crossover in untwinned YBa2Cu3O7-δ single crystals // Journal of Alloys and Compounds 509 (2011) р. 4553–4556.
21. R. V. Vovk, Z. F. Nazyrov, M. A. Obolenskii, I. L. Goulatis, A. Chroneos, V.M. Pinto Simoes / Phase separation in oxygen deficient НоBa2Cu3O7-δ single crystals: effect of high pressure and twin boundaries. // Philosophical Magazine V. 91, №17,11 (2011), P. 2291-2302.
22. R.V. Vovk, M.A. Obolenskii, Z.F. Nazyrov, I.L. Goulatis, A. Chroneos / Electro-transport and structure of 1-2-3 HTSC single crystals with different plane defects topologies // Journal of Materials Science: Materials in Electronics (2012) 23:1255–1259 DOI 10.1007/s10854-011-0582-8.
23. Chroneos A., Vovk R.V., Goulatis I. / Oxygen self-diffusion in apatites // Chemical Monthly (2012) –V.143. –P.345-353. DOI 10.1007/s00706-011-0696-y REVIEW.
24. R.V. Vovk, Z.F. Nazyrov, I.L. Goulatis, A. Chroneos / Metal-to-insulator transition in Y1-xPrxBa2Cu3O7-δ single crystals with various praseodymium content // Physica C 485 (2013) p. 89-91 http://dx.doi.org/10.1016/j.physc.2012.09.017.
25. R.V. Vovk, N.R. Vovk, O.V. Shekhovtsov, I.L. Goulatis, A. Chroneos / C-axis hopping conductivity in heavily Pr-doped YBCO single crystals // Supercond. Sci. Technol. 26 (2013) 085017.
26. A.L. Solovjov, M.A. Tkachenko, R.V. Vovk, and A. Chroneos / Fluctuation conductivity and pseudogap in HoBa2Cu3O7-δ single crystals under pressure with transport current flowing under an angle 45◦ to the twin boundaries // Physica C 501 (2014) p. 24-31 http://dx.doi.org/10.1016/j.physc.2014.03.004.
27. R.V. Vovk, N.R. Vovk, G.Ya. Khadzhai, I.L. Goulatis, A. Chroneos / Effect of praseodymium on the electrical resistance of YBa2Cu3O7-δ single crystals // Solid State Communications, Volume 190, Pages 18–22 (2014)
28. Ruslan V. Vovk, Georgij Ya. Khadzhai, Oleksandr V. Dobrovolskiy / Transverse conductivity in PryY1-yBa2Cu3O7-δ single crystals in wide range of praseodymium concentration / Appl. Phys. A (2014) 117: 997-1002 DOI: 10.1007/s00339-014-8670-2.
29. R.V. Vovk, N.R. Vovk, G.Ya. Khadzhai, Oleksandr V. Dobrovolskiy / Resistive measurements of the pseudogap in lightly Pr-doped Y1-yPryBa2Cu3O7-δ single crystals under high hydrostatic pressure // Solid State Communication 204 (2015) 64-66.
30. R.V. Vovk, G.Ya. Khadzhai, Oleksandr V. Dobrovolskiy, Z.F. Nazyrov / Transverse resistance of YBa2Cu3O7-δ single crystals // Current Applied Physics (2015) DOI: 10.1016/j.cap.2015.02.016.
31. A. Chroneos and R. V. Vovk / Modeling self-diffusion in UO2 and ThO2 by connecting point defect parameters with bulk properties // Solid State Ionics 274 (2015) 1-3.
32. A. Chroneos and R. V. Vovk / Silicon diffusion in germanium described by connecting point defect parameters with bulk properties // Mater. Res. Express 2 (2015) 036301 doi:10.1088/2053-1591/2/3/036301.
33. R.V. Vovk, G.Ya. Khadzhai, Oleksandr V. Dobrovolskiy, Z.F. Nazyrov, and A. Chroneos / Transverst resistance in HoBa2Cu3O7-δ single crystals // Mod. Phys. Lett. B Vol. 30 (2016) 1550232 (8 pages) DOI: 10.1142/S0217984915502322.
34. A.L. Solovjov, L.V. Omelchenko, R.V. Vovk, O.V. Dobrovolskiy, S.N. Kamchatnaya, D.M. Sergeyev / Peculiarities in the pseudogap behavior in optimally doped YBa2Cu3O7-δ single crystals under pressure up to 1 GPa // Current Applied Physics 16 (2016) 931-938.
35. M.A. Hadi, R.V. Vovk and A. Chroneos / Physical properties of the recently discovered Zr2(Al1-xBix)C MAX phases // Journal of Materials Science: Materials in Electronics (2016) 27: 11925-11933 DOI 10.1007/s10854-016-5338-z.
36. A.L. Solovyov,L.V. Omelchenko, V.B. Stepanov, R.V. Vovk, H.-U. Habermeier, P. Przyslupski and K. Rogacki / Specific temperature dependence of pseudogap in YBa2Cu3O7-δ nanolayers // Physical Review B 94, 224505 (2016).
37. O.V.Dobrovolskiy, V.V. Sosedkin, R. Sachser, V.A. Shklovskij, R.V. Vovk, M. Huth / Zero-Bias Shapiro Steps in Asymmetric Pinning Nanolandscapes // J Supercond Nov Magn (2017) 30: 735-741 doi:10.1007/s10948-016-3642-8.
38. R.V. Vovk, G.Y. Khadzhai, Z.F. Nazyrov, S.N. Kamchatnaya / Effect of hydrostatic pressure on the conductivity of YBa2Cu3O7-δ single crystals in a broad range of temperature and oxygen content // Solid State Communications 255-256 (2017) 20-23.
39. M.A. Hadi, M. Roknuzzaman, A. Chroneos, S.H. Naqib, A.K.M.A. Islam, R.V. Vovk and K. Ostrikov / Elastic and Thermodynamic Properties of new (Zr3-xTix)AlC2 MAX-Phase solid solutions //Computation Materials Science 137 (2017) 318-326.
40. Yu.V. Bessmolniy, G.Ya. Khadzhaj, V.I. Beletskii, D.V. Rokhmistrov, R.V. Vovk, I.L. Goulatis, A. Chroneos / Electro and heat transfer in Cd0.22Hg0.78Te single crystals in the temperature range of their practical applications // Journal of Low Temperature Physics (2018),Volume 190, Issue 1–2, pp 39–44 DOI 10.1007/s10909-017-1810-2.
41. O.V. Dobrovolskiy, R. Sachser, M. Huth, V.A. Shklovskij, R.V. Vovk, V.M. Bevz, and M. Tsindlekht / Radiofrequency generation by coherently moving fluxons / Appl. Phys. Lett. 112, 152601–1-5 (2018) arXiv:1804.00856.
42. S Christopoulos; E Sgourou; R Vovk; Alexander Chroneos; C A Londos / The CiCs(SiI)n defect in silicon from a density functional theory perspective // Materials (Basel). (2018) 11(4): 612. doi:10.3390/ma11040612.
43. N. Kuganathan, A. Kordatos, M.E. Fitzpatrick, R.V. Vovk, A. Chroneos / Defect process and lithium diffusion in Li2TiO3 // Solid State Ionics (2018) 327:93-98.
44. O.V. Dobrovolskiy, V.M. Bevz, M.Yu. Mikhailov, O.I. Yuzephovich, V.A. Shklovskij, R.V. Vovk, M.I. Tsindlekht, R. Sachser, and M. Huth / Microwave emission from superconducting vortices in Mo/Si superlattices // Nature Communications (2018) 9:4927 DOI:10.1038/s41467-018-07256-0.
45. V.A. Shklovskij, V.V. Kruglyak, R.V. Vovk, and O.V. Dobrovolskiy / Role of magnons and the size effect in heat transport through an insulating ferromagnet/insulator interface // PRB 98, 224403 (2018) DOI: 10.1103/PhysRevB.98.224403.
46. O. V. Dobrovolskiy, R. Sachser, V. M. Bevz, A. Lara, F. G. Aliev,V. A. Shklovskij, A. I. Bezuglyj, R. V. Vovk, and M. Huth / Reduction of microwave loss by mobile fluxons in grooved Nb films //Phys. Status Solidi Rapid Research Letters. (2019), 13, 1800223 (1 of 5) DOI:10.1002/pssr.201800223, arXiv:1805.10882.
47. Navaratnarajah Kuganathan, Poobalasuntharam Iyngaran, Ruslan Vovk, and Alexander Chroneos / Defects, dopants and Mg diffusion in MgTiO3 // Sci. Rep. (2019) 9:4394 https:doi.org/10.1038/s41598-019-40878-y.
48. O.V. Dobrovolskiy, R. Sachser, T. Brächer, T. Fischer, V.V. Kruglyak, R.V. Vovk, V.A. Shklovskij, M. Huth, B. Hillebrands, and A.V. Chumak / Magnon-Fluxon interaction in a ferromagnet/superconductor heterostructure Nature Physics 15, 477-482 (2019), arXiv:1901.06156.
49. A. Hadi, U. Monira, Alex Chroneos, Saleh Naqib, A K M Azharul Islam, N. Kelaidis, R. V. Vovk, / Phase stability and physical properties of (Zr1-xNbx)2AlC MAX phases // J Phys. and Chem. Solids 132 (2019) 38-47.
50. A Bezyglyj, V Shklovskij, V. Kruglyak, and R.V. Vovk / Spin Seebeck effect and phonon energy transfer in heterostructures containing layers of a normal metal and a ferromagnetic insulator // Phys Rev B 99, 134428 (2019).
51. Dobrovolskiy, Oleksandr V.; Sachser, Roland; Bunyayev, Sergiy; Navas, David; Bevz, Volodymyr; Zelent, Mateusz; Śmigaj, Wojciech; Rychły, Justyna; Krawczyk, Maciej; Vovk, Ruslan; Huth, Michael; Kakazei, Gleb / Spin-Wave Phase Inverter upon a Single Nanodefect / ACS Applied Materials & Interfaces 11 (2019) 17654-17662.
52. O.V. Dobrovolskiy, V.M. Bevz, E. Begun, R. Sachser, R.V. Vovk, and M. Huth / Fast dynamics of guided magnetic flux quanta // Physical Review Applied 11, 054064 (2019).
53. A. L. Solovjov, E. V. Petrenko, L. V. Omelchenko, R.V. Vovk, I. L. Goulatis, A. Chroneos / Effect of annealing on the pseudogap state in untwinned YBa2Cu3O7-δ single crystals // Scientific Reports (2019) 9:9274 https://doi.org/10.1038/s41598-019-45286-w.
54. Alexei I. Bezuglyj, Valerij A. Shklovskij, Ruslan V. Vovk, et al. / Local flux-flow instability in superconducting films near Tc // DOI: 10.1103/PhysRevB.99.174518.
55. A.I. Bezuglyj, V.A. Shklovskij, V.V. Kruglyak, R. V. Vovk / Temperature dependence of the magnon-phonon energy relaxation time in a ferromagnetic insulator // Phys. Rev. B 100, 214409 (2019).
56. A.L. Solovjov, L.V. Omelchenko, E.V. Petrenko, R.V. Vovk, V.V Khotkevych, and A. Chroneos / Peculiarities of pseudogap in Y0.95Pr0.05Ba2Cu3O7-δ single crystals under pressure up to 1.7 GPa" // Scientific Reports (2019) 9:20424 | https://doi.org/10.1038/s41598-019-55959-1.
57. E. N. Sgourou, Y. Panayiotatos, K. Davazoglou, A. L. Solovjov, R. V. Vovk, and A. Chroneos / Self-diffusion in perovskite and perovskite related oxides: insights from modeling // Applied Sciences 2020, 10 (7), 2286.
58. O.V. Dobrovolskiy, C. Gonzalez-Ruano, A. Lara, R. Sachse, V.M. Bevz, V.A. Shklovskij, A.I. Bezuglyj, R.V. Vovk, M. Huth, and F.G. Aliev / Moving flux quanta cool superconductors by a microwave breath // Communications Physics | (2020) 3:64| https://doi.org/10.1038/s42005-020-0329-z|www.nature.com/commsphys.
59. Alexander Grib, Ruslan Vovk, Sergiy Savich, Volodymyr Shaternik / IV-characteristics and power of emission from stacks of long Josephson junctions with Gaussian spread of critical currents // Applied Nanoscience https://doi.org/10.1007/s13204-020-01279-0.
60. Edwin Gevorkyan, Miroslaw Rucki, Ruslan Vovk, Vladimir Chishkala / Nanoscale composites based on Al2O3 and SIC prepared by electroconsolidation method // Engineering for Rural Development, Jelgava, 20.-22.05.2020.
61. Navaratnarajah Kuganathan, Ruslan V. Vovk, Alexander Chroneos / Mayenite electrides and their doped forms for oxygen reduction reaction in solid oxide fuel cells // Energies 2020, 13,4978; doi:10.3390/en13184978.
62. Edwin Gevorkyan,Tatiana Prikhna, Ruslan Vovk, Miroslaw Rucki, Zbigniew Siemiatkowski, Wojciech Kucharczyk, Vladymir Chishkala, LeszekChałko / Sintered nanocomposites ZrO2-WC obtained with field assisted hot pressing // Composite Structures Available online 14 December 2020, 113443.
63. G.Ya. Khadzhaj, A.V. Matsepulin, A. Chroneos, Ι.L. Goulatis, R.V. Vovk / Influence of high pressure on the temperature dependence of electrical resistivity of Y1-xPrxBa2Cu3O7-δ single crystals / Solid State Communications 327 (2021) 114205.
64. Khadzhai, G.Y., Kamchatnaya, S.N., Korobkov, M.V., Vovk, R.V., Dobrovolskiy, O.V. / High-pressure effects on basal-plane conductivity of YPrBCO single crystals // Current Applied Physics, 2022, 39, стр. 311–316.
65. Chroneos, A., Khadzhai, G.Y., Goulatis, I.L., ... Korobkov, M.V., Vovk, R.V. / Effect of high pressure on temperature dependences of the resistivity in the ab-plane of Y0.77Pr0.23Ba2Cu3O7-δ single crystals // Journal of Materials Science: Materials in Electronics, 2022, 33(13), стр. 9875–9884.
66. Sgourou, E.N., Daskalopulu, A., Tsoukalas, L.H., Vovk, R.V., Chroneos, A. / Seventy-Five Years since the Point-Contact Transistor: Germanium Revisited // Applied Sciences (Switzerland), 2022, 12(23), 11993.
67. Gevorkyan, E.S., Nerubatskyi, V.P., Vovk, R.V., Chyshkala, V.O., Kislitsa, M.V. / Structure Formation in Silicon Carbide–Alumina Composites during Electroconsolidation // Journal of Superhard Materials, 2022, 44(5), pp. 339–349
68. Sgourou, E.N., Daskalopulu, A., Goulatis, I., Vovk, R.V., Chroneos, A. / Modelling the Defect Processes of Materials for Energy Applications // Applied Sciences (Switzerland), 2022, 12(19), 9872
69. Alexander Grib, George Khadzhai, Sergey Petrushenko , Sergey Dukarov, Maksim Kislitsa, Tatiana Prikhna, Tetyana Serbenyuk, Alexander Samsonik, Volodymyr Sukhov, Ruslan Vovk / The electrical resistivity of multi-phase systems based on the Ti3AlC2 hexagonal phase at low temperatures // Physica Status Solidi (B) Basic Research, 2023.
70. Malykhin, S.V., Minenkov, A.A., Kopylets, I.A., R.V. Vovk, Surovitskiy, S.V., Borisova, S.S. / Structure and electrical conductivity of Ti-Zr-Ni films of quasicrystalline and related crystalline phases // Journal of Alloys and Compounds, 2023, 965, 171386
71. George Khadzhai, Yoannis Goulatis, Alexander Chroneos, Alexander Feher and Ruslan Vovk. Comparative Analysis of the Irradiation with Medium Fluences of High-Energy Electrons and Pr Doping on the Fluctuation Conductivity of YBa2Cu3O7-δ Single Crystals. Appl. Sci. 2024, 14, 6536. https://doi.org/10.3390/app14156536 https://www.mdpi.com/journal/applsci
72. G.Ya. Khadzhai, I. Goulatis, A. Chroneos, M.V. Kislitsa, S.M. Kamchatna, A. Feher, and R.V. Vovk. The effect of medium doses electron irradiation on the scattering of charge carriers in YBa2Cu3O7-δ single crystal. J Mater Sci: Mater Electron, (2024) 35:1152. https://doi.org/10.1007/s10854-024-12867-z
73. Hevorkian, E.S., Nerubatskyi, V.P., Vovk, R.V., Szumiata, T., Latosińska, J.N. Foamy ceramic filters and new possibilities of their applications. Ceramics International, 2024, 50(4), p. 6961–6968. https://doi.org/10.1016/j.ceramint.2023.12.046
74. Chroneos, A., Goulatis, I.L., Solovjov, A., Vovk, R.V. The Evolution of Solid Oxide Fuel Cell Materials. Applied Sciences (Switzerland), 14(1), 69 (2024). https://doi.org/10.3390/app14010069
75. V. V. Ivzhenko, R.V. Vovk, E. S. Hevorkian, T. O. Kosenchuk, V. O. Chishkala, V. V. Chernyavsky, N. O. Shamsutdinova. Investigation of electrospark sintering of composites of SIC - TIC, SIC - VC systems. Materials 2025, 18, 508.

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