DMITRY ZHUKHOVITSKII

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DMITRY ZHUKHOVITSKII

• Institute of High Temperatures
• Russian Academy of Sciences

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Education

•   1997 defended the Doctor of Physical and
  Mathematical Sciences (Dr. Habil.) dissertation
•  1986 defended the Candidate of Physical and
  Mathematical Sciences dissertation
• 1981 graduated from the Moscow State University

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Career / Employment

• 2001 a title of the Senior Researcher 
• 2000 stayed in France (Laboratoire de
  Physique de la Matière Condensée, Université de
  Nice Sophia Antinopolis, une bourse de
  recherche scientifique et technique de l'OTAN)
• 1998 stayed in Germany (Freie Universität
  Berlin) as an Alexander von Humboldt research
  fellow

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• 1998 Leading Researcher of the Theoretical
  Department, Institute of High Temperatures,
  Russian Academy of Sciences
• 1991-1992 stayed in Germany (Philipps-Universitä
  t Marburg) as an Alexander von Humboldt research
  fellow
• 1990 Senior Researcher of the Theoretical
  Department, Institute of High Temperatures,
  Russian Academy of Sciences
• 1982 Researcher of the Theoretical Department,
  Institute of High Temperatures, Russian Academy
  of Sciences
• 1981 Junior Researcher of the Theoretical
  Department, Institute of High Temperatures,
  Russian Academy of Sciences

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Specialization
- low-temperature dusty plasma

- plasma and dense vapors containing clusters
- molecular dynamics simulation
- gas phase systems containing small droplets
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Current field of research

• Investigation of cluster properties in
  supersaturated vapors at relatively high
  temperatures using molecular dynamics. The
  structure of a surface with significant
  curvature the density profile, Tolman length,
  and other characteristics.

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Publications

• 36 articles in refereed journals
• 19 publications in proceedings of the conferences

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Foreign languages

• Russian (mother tongue)
• English (very good), German (good)
• French (poor)

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References in Germany

• Prof. F. Hensel (Philipps-Universität
• Marburg)
• Prof. E. Illenberger (Freie Universität Berlin)
• Prof. W. Ebeling (Humboldt Universität
• Berlin) 

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The list of essential publications

• Zhukhovitskii D.I. Molecular Dynamics
  Investigation of the Microstructure of a
  Liquid--Gas Interface. JETP (Journal of
  Experimental and Theoretical Physics), 2002, vol.
  121, no. 2, pp. 396-405.
• Zhukhovitskii D.I. Energy characteristics of the
  surface of small clusters. Zhurn. Fiz. Khimii,
  2001, vol. 75, no. 7, pp. 1157-1166.
• ten Bosch A. and Zhukhovitskii D.I. Kinetic and
  Numerical Approaches to Nucleation and Growth
  During a First Order Phase Transition. Technical
  Proceedings of the First International Conference
  on Computational Nanoscience. Hilton, Head
  Island, South Carolina, U.S.A., March 19-21,
  2001, pp. 141-144.
• Zhukhovitskii D.I. "Hot" Clusters and Volume
  Condensation in Plasma. Proceedings of the
  Seminar "Dusty Plasma". Invited lectures.
  Petrozavodsk, Russia, 2000 (in Russian).

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• Zhukhovitskii D.I. and Illenberger E. Kinetics of
  Nucleation of Electronegative Molecules on
  Krypton Film at Cryogenic Temperatures. Izv.
  Akad. Nauk, Ser. Fiz., 2000, vol. 64, no. 8, pp.
  1538-1543 (in Russian).
• Zhukhovitskii D.I. Structure Transition in Hot
  Small Clusters. J. Chem. Phys., 1999, vol. 110,
  no. 16, pp. 7770-7778.
• Zhukhovitskii D.I. Hot Clusters in Supersaturated
  Vapor. In Progress in Physics of Clusters, eds.
  G.N. Chuev, V.D. Lakhno, and A.P. Nefedov, World
  Scientific Publ., Singapore, 1998, pp. 71-101.
• Zhukhovitskii D.I. Structure Transition in Small
  Gaslike Clusters. JETP (Journal of Experimental
  and Theoretical Physics), 1998, vol. 113, no. 1,
  pp. 181-190.
• Zhukhovitskii D.I. Homogeneous Nucleation in a
  Vapor with Nonspherical Clusters. Zhurn. Fiz.
  Khimii, 1997, vol. 71, no. 3, pp. 475-479.

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• Zhukhovitskii D.I. The Influence of Nonspherical
  Shape of Liquid Phase Embryos on the Rate of
  Homogeneous Nucleation. Teplofiz. Vys. Temp.,
  1997, vol. 35, no. 3, pp. 397-403.
• Zhukhovitskii D.I. Investigation of Cluster
  Evolution in the Three-Temperature System by
  Molecular Dynamics Method. Izv. Akad. Nauk, Ser.
  Fiz., 1997, vol. 61, no. 7, pp. 1687-1690.
• Zhukhovitskii D.I. On the Phonon Mechanism of
  Cluster Evaporation. JETP (Journal of
  Experimental and Theoretical Physics), 1996, vol.
  109, no. 3, pp. 839-851.
• Zhukhovitskii D.I. Size-Corrected Theory of
  Homogeneous Nucleation. J. Chem. Phys., 1994,
  vol. 101, pp. 5076-5080.

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• Zhukhovitskii D.I., Thermodynamics of Alkali
  Metal Vapor Plasma in Subcritical Region.
  Teplofiz. Vys. Temp., 1989, vol. 27, no. 1, p.
  15-22.
• Zhukhovitskii D.I., Khrapak A.G., and Yakubov
  I.T. Ionization Equilibrium in Strongly Non-Ideal
  Plasma with Condensed Disperse Phase. Teplofiz.
  Vys. Temp., 1984, vol. 22, no. 5, p. 833-840.
• Zhukhovitskii D.I. and Yakubov I.T., Relaxation
  Processes in Weakly Non-Euqilibrium Plasma with
  Condensed Disperse Phase. Teplofiz. Vys. Temp.,
  1985, vol. 23, no. 5, p. 842-848.
• Zhukhovitskii D.I., On Resonant Absorption of
  Electromagnetic Waves in Plasma with Condensed
  Disperse Phase. Teplofiz. Vys. Temp., 1985, vol.
  23, no. 6, p. 1050-1057.

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DUSTY PLASMA
Dusty plasma (plasma with condensed disperse
phase) is a low-temperature plasma containing
solid or liquid mesoscopic particles. If the
electron work function of the particle material
is sufficiently low, an equilibrium plasma may
exist, in which electrons are produced by the
thermonic emission from particle surface, and the
particles are similar to positive ions. Under the
conditions typical for low-temperature plasma
(temperatures about 2000 K and electron densities
of the order of 1012 cm-3), the plasma is highly
nonideal in the parameter of interparticle
interaction. It was first predicted and then
experimentally confirmed that a short-range
ordering similar to that taking place in a liquid
may take place in equilibrium dusty plasma.
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• This plasma has unusual kinetic properties.
  Investigation of the ambipolar diffusion in the
  system of positively charged particles and
  electrons emitted by them shows that the plasma
  boundary almost preserves its position during a
  considerable time interval due to a dependence of
  the diffusion coefficient of the concentration of
  particles. Thus, the diffusion equation is highly
  nonlinear.
•  

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• The spatial distribution of electrons is not
  uniform a layer is formed in the neighborhood of
  the particle surface, which screens particle
  charge. The presence of these electrons results
  in the emergence of a resonant absorption of
  electromagnetic radiation in dusty plasma, whose
  complex dielectric permeability is essentially
  modified by screening electrons.
•  

,
Hz
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PHYSICS OF HOT CLUSTERS AND THE THEORY OF
NUCLEATION 

• At relatively high temperatures and vapor
  densities (typically, above the triple point
  values of corresponding substance), small
  clusters present in the vapor are shapeless
  formations rather than liquidlike droplets.
  Especially, this refers to the lightest clusters
  containing less than 10 molecules. Such clusters
  form sets of chains, in which each molecule has
  no more than two nearest neighbors, and the
  entire cluster has the minimum number of links
  (bonds) between molecules g 1 (g is the number
  of molecules pertaining to a cluster, or the
  cluster size).

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An adequate model, which is conventionally called
the virtual chain model, was developed to account
for such states. This model predicts the
existence of a structural transition from the
compact structure (droplet) to chainlike one,
which must occur as the number of molecules in
the cluster decreases at sufficiently high
temperature. This effect was discovered during
the computer simulation of argonlike clusters
(particles interacting via the Lennard-Jones 12-6
potential) using molecular dynamics (MD) method.

The ratio of cluster average potential energy to
the energy of a virtual chain drops from high
values characteristic of a compact structure to
unity as the reduced temperature is increased,
which is indicative of a structural transition.
At g gt 10, the cluster structure is no longer
chainlike a core surrounded by a surface layer
is steadily formed as g is increased. It follows
from the virtual chain model that the partition
function of a light cluster is proportional to g
like for a macroscopic droplet. The only
difference is that all molecules of the light
cluster pertain to its surface, while for the
large cluster, most of them are located in the
bulk of its core. This makes it possible to
construct an interpolation formula that unifies
both extremes assuming that every thermodynamic
function of the cluster depends linearly on the
numbers of molecules in its core and on its
surface.
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• Conventionally, a molecule is called the core
  one if it has a number of nearest neighbors,
  which is close to that in a bulk liquid. The rest
  molecules are called the surface ones. To
  distinguish between these two kinds, the cluster
  with an arbitrary size is represented as a
  spherical core surrounded by a layer of surface
  molecules

The density in the cluster core is assumed to be
equal to that in a bulk liquid, the density in
the surface layer, whose thickness l is
independent of g, differs from the latter by the
factor of h. The number of molecules on cluster
surface gs is related to the total number g in
the following way

where the product hl appears to be close to 0.8
for most substances. This relation, along with
the above-mentioned linear interpolation for
cluster chemical potential, allows one to
calculate cluster size distribution and the rate
of homogeneous nucleation in a supersaturated
vapor J. As is seen, gs is proportional to
cluster surface area only if g tends to infinity
at finite g, this is not the case, and the size
corrections to thermodynamic functions can be
considerable. In particular, J may differ by
several orders of magnitude from the value
calculated using the classical nucleation theory
Jcl .
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• It was experimentally detected (F.Hensel,
  H.Uchtmann et al) that during the nucleation in
  mercury vapor, J exceeds Jcl by almost 40 orders
  of magnitude. On the basis of developed theory,
  this "nucleation anomaly" was successfully
  accounted for.

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• The definition of a cluster involved in the
  virtual chain model implies that the cluster is a
  set of molecules each having at least one
  neighbor situated at the distance less than rb
  and pertaining to the same cluster (this is
  almost similar to the Stillinger definition). It
  was shown that this definition yields the same
  value of cluster size (g) as the thermodynamic
  definition based on Gibbs's equimolar radius
  (ge), if rb is equal to the coordinate of the
  first minimum of the radial distribution function
  in bulk liquid. MD simulation is indicative of
  the fact that both definitions are identical to a
  great accuracy at g gt 200 for smaller clusters,
  g deviates from ge noticeably, because such
  clusters consist entirely of the surface
  molecules, and the thermodynamic definition
  looses its meaning.

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• Thermodynamically correct definition of the
  cluster size makes it possible to introduce the
  size-dependent effective surface tension
  coefficient and surface energy per unit surface
  of a cluster, which mimic fundamental properties
  of the surface with a considerable curvature. A
  good correspondence between the surface energy of
  argonlike clusters calculated using developed
  model and obtained during MD simulation has been
  obtained in the entire range of the equimolar
  cluster radius g1/3 from 21/3 to 10. The
  calculation of the Tolman length leads to a small
  positive value d 0.42 (in units of the radius
  of molecular cell in bulk liquid).
• Particles that constitute a cluster are involved
  in the Brownian motion. The emergence of smooth
  portions of the path in the neighborhood of
  cluster surface are obvious in the figure. The
  time evolution of the velocity autocorrelation
  function of a particle and the mean square of its
  displacement in the cluster were investigated. It
  was shown that the velocity autocorrelation
  function can be represented as a sum of two
  exponents with the decay times, which differ by
  an order of magnitude. The long decay time
  corresponds to the capillary wave-like collective
  motion in the cluster surface layer. The
  self-diffusion coefficient of a particle in the
  cluster was determined in MD simulation. It
  proves to increase sharply as the cluster surface
  is approached, which is indicative of the
  collective transport mechanism in the surface
  region.

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To investigate the surface transport phenomena,
we define cluster surface as a set of surface
particles. For MD simulation, we use the
following definitions. If two particles are
located at the distance closer than rb , each of
them have a bond. A particle 1 is called the core
one if it has more than four bonds and there
exists at least one particle 2 such that the
conditions
are satisfied. With these definitions, the
typical configurations of an argonlike cluster
and its cross section are as follows
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The core particles are shown in blue the surface
ones, by cyan the surface virtual chains are
shown in red. Note that the surface particles
form a monolayer on the core. The average number
of particles in a cluster F(b), which have b
bonds, (the distribution over the number of
bonds) was determined using MD simulations for
the surface and core particles as well as for the
entire cluster.
The distribution proved to be bimodal. In figure,
simulation results (dots) are fitted by the sum
of two Gaussian exponents for the surface and
core particles, and for the entire cluster (red,
blue, and green solid lines, respectively). Note
that the distribution for the core particles is
very close to that for a particle in the center
of a cluster. Thus, two phases coexist in the
cluster the surface and core ones. Dependence of
the numbers of particles in these phases on g is
in a good agreement with estimates by the
above-discussed model. Also, it was demonstrated
that evaporating particles detach predominantly
from the surface virtual chains.
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CLUSTER PLASMA
Cluster plasma is a plasma, whose properties are
essentially defined by the presence of clusters
consisting of tens or hundreds of molecules. An
example of such plasma is dense cesium vapor in
the vicinity of the critical point. On the basis
of developed description of small clusters and
with due regard for the volume exclusion in a
dense system, the equation of state and
ionization equilibrium equation were obtained.
The latter has provided a first consistent
interpretation of the anomalous conductivity
phenomenon, which implies both extremely high
values of plasma electric conductivity along the
saturation line and the decrease of electric
conductivity with the increase of the temperature
at isobar.
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Another example of cluster plasma is a plasma,
which is formed during the irradiation of aerosol
by laser pulse. Clusters present in this plasma
absorb laser radiation intensively, so the state
parameters are close to those at the saturation
line. This results in a fast heating and in
lowering of the laser breakdown threshold by
orders of magnitude.