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The development of the thermophysical foundation for design and production of new materials is one of the main goals of the Institute's activity. We focused our attention on the following investigations:

  • high-rate, reliable, and controllable processes of film deposition, powder production, and plasmachemical synthesis in supersonic gas flows, as well as laser ablation;

  • equilibrium and metastable diagrams for crystal-forming inorganic materials;

  • thermodynamics and kinetics of phase transitions and chemical reactions in homogeneous and heterogeneous materials in the condensed state.

Heat and mass transfer of  the process in crystal-growing setups was studied by using the methods of physical and mathematical modeling.

Recently we researched how gas-phase processes in the gas mixture, which were activated by electron-beam plasma, affect the characteristics of the film deposit. It was established that gas-phase condensation is crucial for film growth.

We studied the chemical and physical processes during the multicomponent film deposition by laser ablation. The following laser-induced processes were investigated: the kinetics of particles scattering after laser-induced evaporation into a buffer gas, gaseous reactions in a laser torch and conditions for cluster formation, the dynamics of torch-substrate interaction and the formation of the crystal structure in a film. We revealed the conditions of obtaining epitaxial growth of a multicomponent high-temperature superconductor film with a perfect crystal structure.

The complex physical modeling of hydrodynamics and convection heat transfer was performed using the methods of Chokhralski and Stepanoff, the method of horizontally-directed crystallization, etc. We investigated regimes of thermal gravitation-capillary convection both experimentally, and by computer simulation. The mixed and forced isothermal convection was considered by Chokhralski's method for models with different scales, boundary conditions and geometry.

We created completely new methods for studying physical characteristics and phase transitions in melts and solids (the vibration method and the method of penetrating radiation).

The equilibrium and metastable phase diagrams of different oxide, oxide-salt, semiconductor, and metallic systems used for the growth of crystals which are applicable in different technologies, were studied in detail. For example, those used in laser technology (rear-earth aluminum and gallium garnets), crystals for nonlinear optics (potassium-titanyl-phosphate, barium borate, lithium triborate, cesium triborate, cesium-lithium triborate), semiconductor crystals (cadmium-mercury-tellurium, germanium, silicon, lithium atimonide), and crystals of a new generation.

These complex investigations allowed us to propose new methods and to improve the existing technologies for the production of monocrystals and films, as well as to improve their characteristics.

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Monocrystal areas with epitaxial superconductive film of CdBaCuO with a thickness of 300 nm deposited on a sapphire substrate (a high-resolution electronic microscope image). Insertion - the diagram of the low-angle boundary by Burgers.

Setup for the production of film superconductors.

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Flow pattern in the mode of laminar thermal gravitational-capillary convection. The phase diagram of the system Li2O- B2O3. It was revealed that the content of crystallizing phases in this system depends on the thermal and time conditions of the experiment, that is, this system has a «memory». Liquidus curves for substances with incongruent melting, stretch into the metastable zone (both higher or lower than the temperature reaction). It was established that lithium pentaborate and lithium triborate, being substances with incongruent melting, can have a congruent melting point.

Бердников В.С., Борисов В.Л., Марков В.А., Панченко В.И.
Лабораторное моделирование микроскопических процессов переноса в расплаве при выращивании монокристаллов методом вытягивания // Гидродинамика и теплообмен в технологии получения материалов. М. Наука, 1990. С.68-88.

Хайрулин Р.А., Станкус С.В.
Фазовое равновесие в расплавах индий-алюминий // Ж. физ. химии. 1996. Т.70. №7. С.1230-1232.

Berdnikov V.S., Borisov V.L., Markov V.A., Panchenko V.I.
Simulation of the hydrodynamics of melt in pulling crystals with a conical front and anmilav cross section // Heat Transfer-Sov. Res. 1989. V. 21, no.6.P.828-845.

Kaplun A.B., Meshalkin A.B.
Stable and metastablephase equilibrium in system Bi2O3-GeO2 // J. Crystal Growth. 1996. V. 167, issue 1-2. P.171-175.

Khairulin R.A., Stankus S.V.
The study of two-melt phase separation in the Bi-Zn system by the gamma attenuation technique // J. Alloys and Compounds, 1996, Vol.234, P. 260-263.

Predtechensky M.R.
Laser deposition of HTSC films: expansion of laser plazma, deposition of particles, formation of crystal structure and superconducting properties of films // Appl. Superconductivity. 1993. V.1, no. 3-6. P.793-806.

R.G.Sharafutdinov, A.V.Skrynnikov, A.V.Parakhnevich
High-rate deposition of a-Si:H films using flow plasma-chemical method with electron beam activations. // J. Appl. Phys., 1996.  v.79, no.9, P..7274-7277.

   
 

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