Head of the Complex

The activities of the dilatometric group and the "Complex for measuring the thermal expansion of solid nanostructured materials and cryocrystals at low and ultralow temperatures of the B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine" are coordinated by Corresponding Member of the NAS of Ukraine Dolbin Oleksandr Vitoldovich (born 1967), Acting Director of the B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine since 2024, Head of the Department of Thermal Properties and Structure of Solids and Nanosystems of the B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine (2018 - 2024), in 1996 he received the title of Candidate of Technical Sciences, and in 2012 he defended his doctoral dissertation on the topic "Quantum and Dimensional Effects in Thermal Expansion carbon nanostructures", professor. Laureate of the State Prize of Ukraine in the field of science and technology in 2011 for the cycle of works "Quantum effects and structural self-organization in new multifunctional nanomaterials". In 2022 he received the distinction of the National Academy of Sciences of Ukraine "For professional achievements". Corresponding member of the NAS of Ukraine since 2025 . He is the author and co-author of more than 100 scientific works and inventions.

Dilatometric group

The complex belongs to the Department of Thermal Properties and Structure of Solids and Nanosystems of the B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine. The dilatometric group has been engaged in research in the field of low temperatures since 1972. The group includes candidates of physical and mathematical sciences Mykola Vinnikov, Valentin Eselson, Razet Basnukaeva, Serhiy Cherednichenko. Until 2004, the group was headed by candidate of physical and mathematical sciences Oleksandrovsky Anatoly Nikolayevich. Researchers of this group study solidified gases and their solutions, thermal expansion and kinetics of sorption of gas impurities by carbon nanomaterials.

    The tasks that the complex solves::
  • Measurement of thermal expansion of solids and nanostructured and composite materials from room temperature to 1.2 K (sensitivity 10 -11 m).
  • Measurement of thermal expansion of cryocrystals in the temperature range of their existence
  • Determination of the quantitative and qualitative composition of gases sorbed by nanostructured materials.

"Complex for measuring thermal expansion of solid nanostructured materials and cryocrystals at low and ultralow temperatures"

The complex was granted the status of National Heritage of Ukraine by the Resolution of the Cabinet of Ministers of Ukraine No. 1243 dated 04.11.2022. Dilatometric studies are performed on two low-temperature highly sensitive capacitive dilatometers, which allow detecting a change in the size of the sample under study by the value of the interatomic distance. One of the dilatometers is designed to study the thermal expansion of solidified gases in the temperature range of their existence. The second one is designed to study the thermal expansion of any solid samples of arbitrary shape in the temperature range from 1.5 to 300 K. Dilatometers were developed at the B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine. Thermal expansion measurements provide information about specific phase transitions and quantum phenomena in solids [Low Temp. Phys.42, 788 (2016)]. The high qualification of researchers, who have unique modern technical equipment at their disposal, made it possible to solve a number of scientific problems related to the dynamics of the crystal lattice, spin-nuclear conversion, the features of the rotational motion of molecules in the crystal lattice, as well as the thermal expansion and sorption properties of carbon nanostructures.

Thermal Expansion in Crystal Lattice Cold State (T1) Lattice constant: 0.4 nm Temperature Increase -> Hot State (T2) Lattice constant: 0.48 nm

SCHEME OF A LOW-TEMPERATURE DILATOMETRE AND STAGES OF CREATION OF THE COMPLEX:

Low-temperature part of the dilatometer: 1 - capacitive small displacement sensor (sensor), 2 - copper rod, 3 - sapphire rod tip, 4 - differential thermocouple, 5 - heater, 6 - metal casing, 7 - sapphire hemisphere, 8 - sample under study, 9 - thermometer, 10 - sapphire stage, 11 - sapphire pyramids.


The resolution of the dilatometer (2*10-9 cm) is provided by the design (the main elements of the measuring cell are made of a single sapphire crystal) and the high vibrational and temperature stability of the measuring oscillatory circuit, which is located in liquid helium. There are no analogues in the world for the operating temperature range and the range of tasks that the complex is capable of solving.

The complex was created and improved for more than 40 years by teams of several laboratories under the leadership of Academician of the National Academy of Sciences of Ukraine V.G. Manzhelia.

  • 1971-1974 - creation of the world's first dilatometer for measuring the thermal expansion of cryocrystals (from 4.2K);
  • 1985-1989 - Radical modernization of the dilatometer for measuring the thermal expansion of cryocrystals (temperature range extended to 1.2 K);
  • 1991-1997 - creation of the dilatometer for measuring the thermal expansion of nanostructures (sensitivity 10-11 m);
  • 2000-2001 - modernization of the dilatometer for measuring the thermal expansion of nanostructures. Transition to a new measuring base (LakeShore thermometry);
  • 2002-2004 - creation of a low-temperature desorption vacuum gas analyzer (sensitivity 10-7 mol);
  • 2015-2016 - the automation system was improved and new software was developed.

The Complex includes a low-temperature desorption vacuum gas analyzer for determining the quantitative and qualitative composition of gases sorbed by nanostructures

To study the kinetics of impurity sorption by nanostructures, as well as determination of the concentration and qualitative composition of small amounts of impurity gases sorbed in nanomaterials, the group developed and created a vacuum desorption gas analyzer of an original design with a resolution of 10-7 mol. Sorption and desorption of gas impurities by nanomaterial powders are studied in the temperature range of 2-290 K, which allows analyzing thermally activated and tunneling sorption mechanisms. An example of pressure changes during the desorption process of 4He from a graphene oxide sample is shown in Fig. below. [Low Temp. Phys. 39, 1090 (2013)].

Scientific cooperation:

The group carries out a constant exchange of scientific information with scientists from different countries. Based on cooperation with researchers from the Department of Experimental Physics, Umea University (Sweden), Australian Nuclear Science and Technology Organization (Australia) and with the National Scientific Center "Kharkiv Institute of Physics and Technology" (Ukraine), comprehensive studies of fullerite C60, both pure and doped with various gases, are being carried out. Joint studies are being carried out with scientists from the Instituto de Carboquimica, Zaragoza, Spain and Lappeenranta-Lahti University of Technology LUT (Finland). Studies of the thermal properties of single-walled nanotubes (SWCNTs) were carried out in cooperation with researchers from the E. L. Andronikashvili Institute of Physics of the Georgian Academy of Sciences, Tbilisi (Georgia).

Some of the main results obtained by the dilatometric group:

The group investigated the thermal expansion of such exotic objects as solidified gases: Ar, Kr, Ne, H2, HD, D2, CH4, CHD3, CD4, N2, CO2, CO, N2O, NH3, CCl4, CBr4, SF6 and a number of their solid solutions, as well as the thermal expansion of fullerite, various structural materials and crystals used in low-temperature and space technology. In recent years, negative thermal expansion and the phenomenon of orientational polyamorphism of fullerite C60 at liquid helium temperatures have been discovered. The low-temperature thermal expansion of bundles of single-walled carbon nanotubes in the radial direction was investigated. The impurity and quantum effects in the thermal expansion of carbon nanostructures were investigated. The quantum diffusion of helium, hydrogen and neon in fullerite C60 was discovered and investigated. The tunneling nature of the spatial redistribution of 4He and 3He in bundles of carbon nanotubes was revealed. For the first time, the effect of radiation irradiation of bundles of nanotubes with γ-quanta in the atmosphere of various gases on the radial thermal expansion of bundles of nanotubes and their sorption of hydrogen was experimentally investigated. It was shown that irradiation of samples sharply increases the amount of hydrogen chemisorbed by nanotubes. The sorption and subsequent desorption of gaseous impurities 4He, H2, Ne, N2, CH4 and Kr by graphene oxide (GO), glucose-reduced graphene oxide (RGO-GL), and hydrazine-reduced graphene oxide (RGO-Hz) powders in the temperature range 2-290 K were investigated. The effect of thermal reduction on the structure and sorption properties of graphene oxide was investigated. Many of the experimental data obtained were included in reference books and monographs published in Ukraine and the USA.

The results obtained are presented: in four monographs (Begell Hose, AIP Press, Naukova Dumka), in 88 scientific articles (Appl.Phys.Lett., Applied Surface Science, JLTP, FNT), 6 articles over the last 3 years. The total citation index of the works is h-index=21, a total of 1432 citations (as of December 1, 2025). The conducted research was awarded: State Prize in 1977, Prize named to B.I. Verkin of the NAS of Ukraine in 1999, State Prize of Ukraine in the field of science and technology in 2011. Honorary diploma of the NAS of Ukraine for the cycle of works "Kinetics of low-temperature sorption of gases by graphene nanostructures" in 2019. Prize of the President of Ukraine in 2021 for the scientific work "Structure, sorption and thermal properties of carbon nanomaterials and the creation of composites based on them".

Popularization of scientific results and Membership in scientific societies and organizations:

International Conference "Condensed Matter & Low-Temperature Physics"

Corresponding Member of the NAS of Ukraine Dolbyn Oleksandr Vitoldovich is the Chairman of the International Program Committee of the International Conference "Physics of Condensed Matter & Low-Temperature Physics". Basnukaeva R.M. is a member of the Organizing Committee of the Conference.

Scientific Council on the problems of "Molecular Physics, Physics of Cryogenic Liquids and Crystals"

Corresponding Member of the NAS of Ukraine Dolbyn Oleksandr Vitoldovich is a member of the Scientific Council "Molecular Physics, Physics of Cryogenic Liquids and Crystals" at the B.I. Verkin ILTPE of NASU.

Specialized Academic Council for Awarding the Degree of Doctor of Sciences D 64.175.022

Corresponding Member of the NAS of Ukraine, Prof. Dolbin Oleksandr Vitoldovich - Head of the Specialized Academic Council for Awarding the Scientific Degree of Doctor of Sciences D 64.175.02 at the B. I. Verkin ILTPE of NASU.

Thermal Kharkiv Seminars: "Heat Capacity and Thermal Conductivity of Solids at Low Temperatures"

Prof. Dolbin A.V. and Dr. Basnukaeva R.M. are members of the Kharkiv local organizing committee of regular international seminars "Heat capacity and thermal conductivity of solids at low temperatures". Partners and co-organizers of the seminars: V.N. Karazin Kharkiv National University (Kharkiv, Ukraine), Institute of Low Temperatures and Structural Research of the PAN (Wroclaw, Poland), Osaka University (Osaka, Japan), University Autonomous of Madrid (Madrid, Spain).

Prospects for the development of the complex

The complex for measuring the thermal expansion of solid nanostructured materials and cryocrystals at low and ultralow temperatures is open to solving modern problems of condensed matter physics that arise in various scientific institutions of Ukraine, and participates in the implementation of target programs of the National Academy of Sciences of Ukraine and international projects.

Information about the capabilities of the complex and proposals for scientific cooperation are also posted on the LabsArena platform - a modern service for searching for partners, equipment and laboratory services. This allows researchers from different institutions to quickly find access to a unique experimental base and initiate joint research.

Areas of scientific research:

Thermal expansion of carbon composite materials at low temperatures

Information on thermal expansion is necessary when designing and selecting operating modes for new products based on nanomaterials, which are intended for operation in wide temperature ranges. Taking into account the difference in thermal expansion of materials is extremely important, since when temperature conditions change in such structures, significant mechanical stresses arise, which can lead to their destruction. N. A. Vinnikov et al., Low Temperature Physics, 51(9), 1122–1125 (2025).

Quantum diffusion of light impurity particles in carbon nanostructures

For the first time, quantum diffusion of light impurity particles (3He, 4He, H2, D2, Ne) in carbon nanostructures (fullerite C60, carbon nanotubes, graphene-containing structures) was discovered. A. V. Dolbin et al., Fiz. Nizk. Temp. 36, 1352 (2010), [Low Temp. Phys. 36, 1091 (2010)]

A method for thermal reduction of graphene oxide (trGO) has been developed, which is an effective sorbent and suitable for use in biology and medicine, since it does not contain toxic reducing agents and solvents. Using the experimental complex, the influence of oxygen-containing groups and defects on the sorption properties of graphene oxide was revealed. It was established that by thermal reduction it is possible to increase the sorption capacity of this nanostructure by more than an order of magnitude. A.V. Dolbin et al. (Applied Surface Science 361, 213 (2016))

Thermal expansion of fullerite C60

The thermal expansion of fullerite C60 was investigated for the first time at temperatures below 5 K. Negative thermal expansion of fullerite was observed at low temperatures, which indicates the tunneling nature of the rotational states of C60 molecules. The introduction of impurities into the cavities of the fullerite crystal lattice radically changes both the absolute values and the sign of the thermal expansion of the system. The existence of polyamorphous transformations in the orientational glass of fullerite and the effects of tunneling rotation of methane and deuteromethane molecules in the octahedral interstitial cavities of the fullerite crystal lattice of C60 were discovered for the first time. A.N. Aleksandrovskii et al. Fiz. Nizk. Temp. 29, 432 (2003) [Low Temp. Phys. 29, 324(2003)]

Fig. Temperature dependences of the coefficients of linear thermal expansion (1) heating (▲, ●), (2) cooling (□) of the sample (Kr)0.63-C60, (3) - pure C60 (heating and cooling).

Thermal expansion of organic superconductor magnets

The collaboration between the B.I. Verkin ILTPE of NASU and Osaka University (prof. Y. Nakazawa's group) combined the Ukrainian school of high-precision low-temperature dilatometry and Japanese expertise in the synthesis and physics of organic conductors based on BEDT-TTF, which brought new fundamental results in the study of the thermal expansion of organic superconductors. It was possible to detect thermal expansion anomalies and establish a connection between LTEC anomalies and charge fluctuations near the superconducting transition. The results obtained can be used to build ultrasensitive magnetic field sensors. A.V. Dolbin et al., Low Temperature Physics 45 (1), 128-131 (2019)

Thermal expansion of bundles of single-walled carbon nanotubes in the radial direction

The low-temperature coefficient of thermal expansion of bundles of single-walled carbon nanotubes in the radial direction was determined for the first time and the relationship between thermal expansion and heat capacity was analyzed. The effects of saturation of bundles of nanotubes with gas impurities, which lead to a significant increase in the radial thermal expansion of bundles of carbon nanotubes, were explained. A.V. Dolbin et al., Fiz. Nizk. Temp.34, 860 (2008). [Low Temp. Phys. 34, 678 (2008)].