I want to shortly introduce my group.

We are working in B.Verkin Institute for Low Temperature Physics & Engineering, National Academy of sciences of Ukraine. Our scientific interests are thermal and sorption properties of fullerites (C60) and single-walled carbon nanotubes.

 

STAFF

Group leader

Dolbin Aleksander Vitoldovich

Educational background, institutional affiliations

 2012 - Doctor of Physics and Mathematics, 2004-  Senior Researcher, head of the group for dilatometric studies of B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 2000-2004 Researcher, Department of Thermal properties of Molecular Crystals B.Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 1996-2000 STC "Institute for Single Crystals" (Researcher) 1993-1996 National Tecnical University (KhPI) (Graduate Ph.D. in Engineering Science) 1985-1993 National Tecnical University (KhPI) (Graduated With Honors)

Research Experience

1.                 Investigation of the sorptive characteristics of the carbon nanomaterials.

2.                The dilatometric investigations of thermal expansion of carbon nanotubes (pure and doped with gases), fullerites and solid gases.

3.                Computer simulation of physical processes in high electric and magnetic field.

 Selected publications

1. A. V. Dolbin, V. B. Esel'son, V. G. Gavrilko, V. G. Manzhelii, N. A. Vinnikov, S. N. Popov. Kinetics of ⁴He gas sorption by fullerite C₆₀. Quantum effects. Low.Temp.Phys. 36,1091 (2010)

2. A. V. Dolbin, V. B. Esel'son, V. G. Gavrilko, V. G. Manzhelii, N. A. Vinnikov, S. N. Popov and B. Sundqvist. Quantum effects in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with ⁴He. Low.Temp.Phys. 36, 635 (2010)

3. A. V. Dolbin, V. B. Esel'son, V. G. Gavrilko, V. G. Manzhelii, S. N. Popov, N. A. Vinnikov and B. Sundqvist. The low-temperature radial thermal expansion of single-walled carbon nanotube bundles saturated with nitrogen. Low Temp. Phys. 36, 365 (2010)

4. A. V. Dolbin, V. B. Esel'son, V. G. Gavrilko, V. G. Manzhelii, S. N. Popov, N. A. Vinnikov and B. Sundqvist. The effect of sorbed hydrogen on low temperature radial thermal expansion of single-walled carbon nanotube bundles. Low Temp. Phys. 35, 939 (2009)

5. A. V. Dolbin, V. B. Esel’son, V. G. Gavrilko, V. G. Manzhelii, N. A. Vinnikov, S. N. Popov, N. I. Danilenko and B. Sundqvist. Radial thermal expansion of pure and Xe-saturated bundles of single-walled carbon nanotubes at low temperatures. Low Temp. Phys. 35, 484 (2009)

Esel’son Valentin Borisovich, Ph.D. in Physics and Mathematics. Graduated from Kharkov State University in 1970. Since 1968 - a researcher at the Institute for Low Temperature Physics & Engineering of the National Academy of Sciences of Ukraine. He is a author and co-author of about 65 scientific publications, has 3 author’s certificates for inventions. His main publications are concerned with low temperature physics, in particular the thermal, mechanical and dielectric properties of solid hydrogen’s (H₂, D₂), thermal expansion and adsorption properties of fullerite C₆₀ and carbon nanotube, experimental equipment.

1. A.N. Aleksandrovskii, V.B. Esel’son et al., Thermal expansion of single-crystal fullerite at liquid-helium temperature, Low Temp. Phys. 26, 75 2000).

2. A.N. Aleksandrovskii,  V.B. Esel’son et al., Argon effect on thermal expansion of fullerite C60 at helium temperatures, Low Temp. Phys. 27, 245 (2001).

3.  A.V. Dolbin, V.B. Esel’son et al., The effect of sorbed hydrogen on low temperature radial thermal expansion of single-walled carbon nanotube bundles, Low Temp. Phys., 35, 1209 (2009).

4. A.V. Dolbin, V.B. Esel’son et al., Quantum effects in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with 4He, Low Temp. Phys., 36, 797, (2010).

5. A.V. Dolbin, V.B. Esel’son et al., Kinetics of 4He gas sorption by fullerite C₆₀. Quantum effects, Low Temp. Phys., 36, 1352(1210).

 

Vinnikov Nikolay A., Ph.D. in Physics and Mathematics in 2010. Graduated from National Tecnical University (KhPI) in 2005. Since 2007 - a junior researcher at the Institute for Low Temperature Physics & Engineering of the National Academy of Sciences of Ukraine, participant of the group for dilatometric research. An author and co-author of over 30 scientific publications. His main scientific publications are concerned with the thermal and sorption properties of carbon nanotube, An expert in low temperature physics.

1. A. V. Dolbin, V. G. Manzhelii et al., Influence of dissolved oxygen on the thermal expansion and polyamorphism of fullerite C₆₀, Low Temp. Phys. 33, 465 (2007).

2.  A.V. Dolbin, V.B. Esel’son et al., The effect of sorbed hydrogen on low temperature radial thermal expansion of single-walled carbon nanotube bundles, Low Temp. Phys., 35, 1209 (2009).

3. A.V. Dolbin, V.B. Esel’son et al., Quantum effects in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with 4He, Low Temp. Phys., 36, 797, (2010).

EXPERIMENTAL EQUIPMENT

All dilatometric measurements carry out with low temperature (2-100K) high-sensivity capacitance dilatometer. Datailed its construction and measuring technique is described in paper. But in the recent years we principially modernized dilatometer and whole dilatometric complex. Now the sensivity of the dilatometer is 10-9 cm (!). We can measure thermal expansion of cilindrical samples 10 mm in diameter and up to 10 mm high.

Sorption - desorption experiments could be carry out using low-temperature (2-300K) desorption gas analyzer. The investigation technique and the setup design are detailed in paper

 

OBTAINED RESULTS

At present the development, property investigations and commercial applications of new carbon nanosystems are among the top priority trends of the world science and science-based technologies. Recently the authors have obtained fundamentally novel results pointing to a quantum character of carbon nanosystems at low temperatures. They are as follows.

1.                A negative thermal expansion of fullerite has been observed at low temperatures, which suggests the tunnel origin of the rotational states of C₆₀ molecules. Impurities introduced into the voids of the C₆₀ lattice affect drastically both the magnitudes and the sign of the thermal expansion of the system (1).

2.                Quantum diffusion of ³He, ⁴He, Ne atoms and H₂ molecules in C₆₀ has been detected by investigating the sorption – desorption kinetics of gases at low temperature [2 3]. The method was a direct measurement of the pressure of these gases contacting a C₆₀ powder in a closed volume.

3.                An isotopic effect has been detected in the investigation of the thermal expansion of C₆₀ doped with methane and deuteromethane. The effect is caused by the tunnel rotation of the CH₄ and CD₄ molecules in the octahedral interstitials of the C₆₀ lattice [4].

4.                The low temperature coefficient of the thermal expansion of bundles of single-walled carbon nanotubes in the radial direction has been measured for the first time [5]. Negative values of the thermal expansion were observed be low 5.5 K. This novel phenomenon is a manifestation of the lowest-frequency part of the vibrational spectrum of nanotubes at low temperatures. The spectrum is characterized by a negative Gruneisen coefficient, which is typical of bending vibrations of two – dimensional systems. As the temperature increases above 5.5 K, the negative values of the thermal expansion typical for two-dimensional systems change into positive ones characteristics of three-dimensional objects.

5.                Saturation of nanotube bundles with gas impurities triggers an intensive increase in the radial thermal expansion of bundles of carbon nanotubes, which is attributed to the influence of the gas impurity molecules on the bending vibrations of the system. Because of the geometrical features of SWNT bundles, their saturation with an impurity leads to the formation of one-dimensional chains of the impurity molecules in the grooves of the bundles. This structural reordering of the impurity molecules produces a peak in the temperature dependence of the radial thermal expansion coefficient [6].

6.                Experimental evidence has been obtained for the first time which suggests tunneling of ⁴He and ³He atoms in bundles of single-walled carbon nanotubes [7 8]. This results in a considerable increase in the magnitudes of the negative radial thermal expansion of the ⁴He-SWNT and ³He-SWNT systems at T<3.7 and 7K, respectively. An unexpectedly large isotopic effect has been observed due to the higher probability of tunneling of ³He atoms.

The results obtained point to the importance of the influence of quantum effects upon the structure and properties of new carbon nanomaterials. The above results lead us to expect that a controllable introduction of impurities (including quantum ones) will enable modification of the properties of carbon nanosystems in a wide temperature interval.

 

CONTACT INFORMATION

I:

Nikolay A. Vinnikov

B.Verkin institute for low temperature physics & engineering,

 National Academy of sciences of Ukraine,

 47, Lenin Ave., Kharkov,61103,  Ukraine.

Phone: +38-(057)-341-0979

email: vinnikov@ilt.kharkov.ua,  nikolasviltpe@gmail.com

 

Group Leader:

Dr. Alexander Dolbin

 B.Verkin institute for low temperature physics & engineering,

 National Academy of sciences of Ukraine,

 47, Lenin Ave., Kharkov,61103,

 Ukraine.

Phone: +38-(057)-341-0979

Fax. +38-(057)-340-3370, +38-(057)-345-0593

E-mail: dolbin@ilt.kharkov.ua  

http://dolbin.org.ua/en/

http://www.ilt.kharkov.ua/bvi/structure/depart_r/d09/dolbin_e.html

 

http://ltp.aip.org/resource/1/ltpheg/v35/i6/p484_s1?isAuthorized=no