DMITRY ZHUKHOVITSKII

1. DMITRYZHUKHOVITSKII Institute of High Temperatures Russian Academy of Sciences CURRICULUM VITAE

2. 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 CURRICULUM VITAE

3. 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

4. 1998 – Leading Researcher of the Theoretical Department, Institute of High Temperatures, Russian Academy of Sciences • 1991-1992 – stayed in Germany (Philipps-Universität 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

5. Specialization - low-temperature dusty plasma - plasma and dense vapors containing clusters - molecular dynamics simulation - gas phase systems containing small droplets

6. 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. CURRICULUM VITAE

7. Publications • 36 articles in refereed journals • 19 publications in proceedings of the conferences CURRICULUM VITAE

8. Foreign languages • Russian (mother tongue) • English (very good), German (good) • French (poor) CURRICULUM VITAE

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

10. 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).

11. 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.

12. 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.

13. 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.

14. 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. DUSTY PLASMA

15. 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.

16. 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

17. 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).

18. 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 > 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.

19. 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: 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 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 .

20. 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.

21. 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 > 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.

22. 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.

23. 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:

25. 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.

26. 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 forthe 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 anomalousconductivity 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.

28. 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.