Materials physics and mechanics

RAR RUS 1-10 Virginia Commonwealth University Rao

Richmond, USA

Institute of High Temperatures, Russian Academy of Sciences Smirnov

Moscow, Russia

Cluster Growth in Expanding Copper Vapor Atomic clusters have been proposed as building blocks for tailor-made materials with specific combinations of properties. Growth of such clusters from vapor must be understood to enable one to prepare such materials. Here the process of the cluster growth in expanding copper vapor is analyzed by solving the balance equations for atoms, diatomic molecules, and clusters of different sizes as functions of temperature of buffer gas atoms and clusters. Dependence of the average cluster size at the end of the process on expansion time and the initial number density of atoms is studied. Numerical calculations are performed to obtain the realistic character of change of vapor parameters in a jet nozzle. Copper Cluster Growth https://mpm.spbstu.ru/article/2002.7.1/ MPM_5_1_P01.pdf

RAR RUS 11-15 IESL/FORTH Bender M.

Greece

Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FO.R.T.H.) Katsarakis N.

Heraklion, Greece

Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FO.R.T.H.) Kiriakidis G.

Heraklion, Greece

Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering, Russian Academy of Sciences Reizis A.B.

St.Petersburg, Russia

Physical Mechanisms of Enhanced Conductivity in Irradiated InOx Nanocrystalline Films We present experimental data on the conductivity evolution in InOx nanocrystalline (nano-grained) films after UV light irradiation, and its dependence on film thickness. These experimental data are indicative of new irradiation-induced effects in the nanocrystalline matter and used as input in elaboration of a theoretical model describing physical mechanisms of the UV light irradiation-induced enhancement of the conductivity in nanocrystalline films. In the framework of the model, the experimentally detected peculiarities of InOx nanocrystalline films are attributed to the presence of high-density ensembles of grain boundaries in such films. In particular, the enhancement of conductivity in these films is theoretically described as a phenomenon related to irradiation-induced structural transformations of grain boundaries and ionization, whose intensities are highly sensitive to the film thickness. Nanocrystalline Films Conductivity Irradiated Films https://mpm.spbstu.ru/article/2002.7.2/ MPM_5_1_P02.pdf

RAR RUS 16-22 Naval Research Laboratory Pande C.S.

USA

Naval Research Laboratory Masumura R.A.

USA

U.E.S. Inc. Hazzledine

Dayton, USA

Yield Stress of Nanocrystalline Materials Modeling of strengthening by nanocrystalline materials need consideration of both dislocation interactions and sliding due to Coble creep acting simultaneously. Such a mechanism is considered in this paper. It is shown that a model based on using Coble creep (with a threshold stress) for finer grains and conventional Hall-Petch strengthening for larger grains, appears to be most successful in explaining experimental results provided a grain size distribution is incorporated into the analysis to account for a distribution of grain sizes occurring in most specimens. Use of an alternate formalism of Coble creep proposed recently gives a somewhat less satisfactory agreement with experiments. Nanocrystalline Materials Modeling of strengthening Yield Stress https://mpm.spbstu.ru/article/2002.7.3/ MPM_5_1_P03.pdf

RAR RUS 23-30 Ufa State Aviation Technical University Zhilyaev Alexandr P.

Ufa, Russia

Ufa State Aviation Technical University Nurislamova

Ufa, Russia

Universitat Autònoma de Barcelona Suriñach

Bellaterra, Spain

Universitat Autònoma de Barcelona Baró

Bellaterra, Spain

University of Southampton Langdon T.G.

U.K.

Calorimetric Measurements of Grain Growth in Ultrafine-Grained Nickel The process of grain growth in ultrafine-grained nickel was studied using differential scanning calorimetry. Samples of nickel, with mean grain sizes in the range from 100 to 400 nm, were prepared by equal-channel angular pressing, high pressure torsion or combinations of both. It is shown using differential scanning calorimetry that grain growth in these structures begins at temperatures in the range from 500 to 700K and the measured activation energy for grain growth is close to the activation energy for grain boundary self-diffusion. There was also evidence for a decreasing activation energy in the samples prepared by high pressure torsion. Ultrafine-Grained Nickel Grain Growth Calorimetric Measurements https://mpm.spbstu.ru/article/2002.7.4/ MPM_5_1_P04.pdf

RAR RUS 31-38 Institute of Electron Technology Misiuk Andrzej

Warsaw, Poland

Polish Academy of Sciences Bak - Misiuk

Warsaw, Poland

Institute of Electron Technology Kaniewska

Warsaw, Poland

Institute of Semiconductor Physics, RAS Zhuravlev

Novosibirsk, Russia

CNR - IMETEM Raineri

Catania, Italy

Institute of Semiconductor Physics, RAS Antonova

Novosibirsk, Russia

Nanostructured Layers in High Temperature - Pressure Treated Silicon Implanted with Hydrogen / Helium Structural, electrical and photoluminescence properties of single crystalline silicon implanted with hydrogen and helium, Si:H and Si:He (ion doses ≤ 5. 1016 cm-2, energy, E ≤ 200 keV) and subjected to annealing at up to 1470K under hydrostatic pressure up to 1.2 GPa were investigated. The temperature - pressure (HT - HP) treatment of Si:H and Si:He results in creation of nanostructured buried layers containing gas - filled cavities and numerous extended and point defects; the HT - HP treated Si:H structures are not splitted contrary to those annealed under atmospheric pressure. The HT - HP induced effects are related to creation of smaller, nanometer - sized structural defects and to retarded out - diffusion of hydrogen and helium at HP. The buried layers are active in respect of oxygen gettering. The Si:H and Si:He samples indicate visible photoluminescence after subjecting to specific HT - HP treatment. Silicon Si Nanostructured Layers Single crystalline layers https://mpm.spbstu.ru/article/2002.7.5/ MPM_5_1_P05.pdf

RAR RUS 39-42 Institute of Solid State Physics Straumal B.B.

Moscow, Russia

Institute of Solid State Physics Vershinin

Moscow, Russia

Institute of Solid State Physics Asrian

Moscow, Russia

TECHNION-Israel Institute of Technology Rabkin

Haifa, Israel

University of Bremen Kroeger

Bremen, Germany

Nanostructured Vacuum ARC Deposited Titanium Coatings Ti coatings on silicate glass substrates have been produced using a nonfiltered vacuum arc deposition technique. The dependence of the deposition rate on the distance from the cathode both in lateral and transversal directions was investigated. The average roughness, Ra , decreases with the distance, showing a transition area between the microparticle-containing and microparticle-free Ti films. Ra depends strongly on the number of microparticles. A linear dependence of Ra on the discharge current was obtained only for substrates far enough from the cathode. For substrates close to the cathode the dependence is governed by the microparticle density. Transmission electron microscopy (TEM) reveals dense structure with nanograins. Titanium Coatings Nanostructured Coatings https://mpm.spbstu.ru/article/2002.7.6/ MPM_5_1_P06.pdf

RAR RUS 43-46 Institute of Silicate Chemistry, Russian Academy of Sciences Vasilyeva

St.Petersburg, Russia

Institute of Silicate Chemistry, Russian Academy of Sciences Morozova

St.Petersburg, Russia

Institute of Silicate Chemistry, Russian Academy of Sciences Lapshin

St.Petersburg, Russia

Institute Silicate Chemistry of Russian Academy of Science Konakov V.G.

St.Petersburg, Russia

Ceramic Materials with Controlled Porosity The precursors for magnesium aluminate spinel were synthesized by the method of joint crystallization from mixed solutions of magnesium and aluminum salts. The sequence of the MgAl2 O4 phase formation vs starting reagents was studied. Spinel materials with controlled porosity were obtained using the variation of the Al source at nano-sized precursors synthesis, the changes of the sintering regimes and the introducing combustible additive of carbon and sintering aids into the blend. The optimal regimes for the sintering of the ceramic spinel materials with more than 50% porosity were determined. Ceramic Materials MgAl2O4 Method of joint crystallization from mixed solutions https://mpm.spbstu.ru/article/2002.7.7/ MPM_5_1_P07.pdf

RAR RUS 49-55 Institute of Problems of Mechanical Engineering RAS Fedorov

St.Petersburg, Russia

N-7717-2016 7005519053 0000-0003-4116-4821 Institute of Problems of Mechanical Engineering RAS Kolesnikova Anna anna.kolesnikova.physics@gmail.com

St. Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Grain Boundary Dislocation Structures near Triple Junctions in Nano- and Polycrystalline Materials A theoretical model is suggested which describes structural and behavioral features of grain boundary dislocation configurations near triple junctions in nano- and polycrystalline materials. With the elastic interaction between grain boundary dislocations taken into account, we have theoretically examined deviations of spatial arrangement of boundary dislocations near triple junctions, from a periodic arrangement. Also, the local migration of grain boundaries near their triple junctions has been theoretically described, induced by grain boundary sliding in mechanically loaded nano- and polycrystalline materials. In the framework of the model, the key driving force for the local migration is a release of the elastic energy of ensemble of gliding boundary dislocations (carriers of grain boundary sliding) and immobile boundary dislocations (associated with grain boundary misorientation). It is shown that migration is capable of effectively enhancing grain boundary sliding, in which case the combined effects of grain boundary sliding and migration near triple junctions cause plastic flow localization in fine-grained materials, reported in the literature. Grain Boundary Dislocations Triple Junctions Nanocrystalline Materials Polycrystalline Materials https://mpm.spbstu.ru/article/2002.7.8/ MPM_5_1_P08.pdf

RAR RUS 56-60 Universität Wuppertal Körbes

Wuppertal, Germany

Universität Wuppertal Balk

Wuppertal, Germany

Institut für Physikalische Chemie und Elektrochemie Schultze

Düsseldorf, Germany

Nanostructuring of Polymers in Liquid by the Use of Polymer Crazing The development of nanostructures is usually based on UV- or DUV-lithography. Using these techniques, a new set of lithographic masks has to be generated for each step in development. Other methods to create nanostructures are the direct writing techniques like ebeam, but this techniques suffer from very high installation and operation costs. To overcome these cost and time intensive procedures we have developed an in-situ technique which allows to write lateral structures with a resolution of 80 nm over an area of up to 100 µm in square with simultaneous characterization. This method is based on a conventional scanning force microscope modified for the use in a development liquid onto a commercial available PMMA/MA e-beam resist and is independent of the substrate material. Specific variations of the tip force which define the depth of structuring allow even structures with oblique faces. Furthermore it has to be emphasized that negative structures can be processed on the in fact positive resist. The created patterns could act as templates for the deposition of e.g. metals or alloys. This can be followed by further lithographic processes of the presented method. For the structuring a completely new mechanism is used. The polymer chains are not cracked as in e-beam lithography, but the crazing of the polymer is used. With new experiments we can prove the fundamentals of the presented technique. In this presentation we will illustrate the feasibilities of this method with respect to electrochemical applications on several examples. Polymer Nanostructuring UV-lithography DUV-lithography https://mpm.spbstu.ru/article/2002.7.9/ MPM_5_1_P09.pdf