PCSS, V.15, №4, 2014

Abstracts

A.H. Kevshyn

Features of the Structure of GeX₂ (X = S, Se) Chalcogenide Glasses (Review)

Department of General Physics, Lesya Ukrainka Eastern European National University, 13 Volya Avenue, 43025 Lutsk, Ukraine: e-mail:Kevshin_A@ukr.net

This article reviews studies on the structure of chalcogenide glasses obtained from compound GeX2 (X = S, Se). Parameters defining the structure of glassy alloys are usually determined by Fourier transformation of experimental data on X-ray, electron and neutron diffraction. The main structural units of considered glasses are tetrahedrons GeS(Se)4/2 with bond lengths 2,21 ? for Ge-S and 2,36 Å for Ge–Se bonds. The introduction of modifying additions, in particular Ag, increases these bond distances. In glassy alloys of the system Ge0,18Ga0,05Sb0,07S0,70 xSex at x > 0,10 the number of tetrahedra GeS4/2 decreases and new unit structures appear such as edge sharing tetrahedra Ge2S4S2/2 and S3Ge-S-GeS3, and a small number of mixed structural units GeS2Se. With further decreasing of Se content formation of corner sharing tetrahedra GeSe4/2 and edge sharing tetrahedra Ge2Se4Se2/2 is observed. Peculiarities of energy band structure in amorphous and glassy semiconductors due to theoretical models by Hubanov A.I., Cohen, Fritzche, Ovshinsky, Davis-Mott, Anderson are reviewed. It is shown, that each of these models has some advantages and imperfections and can explain experimental data within certain assumptions.
Keywords: glassy alloy; radial distribution function; average interatomic distances; coordination sphere.

B.M.Ruvinskii¹, M.A.Ruvinskii²

The Influence of Thickness Fluctuations on the Electroconductivity and Thermopower of Quantum Semiconductor Wire

1Ivano-Frankivsk National Technical University of Oil and Gas, 15, Carpatska Str., Ivano-Frankivsk, 76000, Ukraine, 2Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine bruvinsky@gmail.com

It was determined the electrical conductivity and thermopower of semiconductor quantum wire conditioned by a random field of Gaussian fluctuations of wire thickness. We present the results for cases degenerate and nondegenerate statistics of carriers. The considered mechanism of relaxation of the charge carriers is essential for sufficiently thin and clean GaAs wire at low temperatures and allows in principle the possibility of increasing the value of thermopower compared to the case of three-dimensional solid model.

Р.М. Пелещак, І.І. Лазурчак, М.В. Дорошенко, Н.Я. Кулик

Моделювання розподілу потенціалу в бар’єрній структурі Шотткі з вбудованим шаром квантових точок

Дрогобицький державний педагогічний університет ім. І. Франка, вул. Стрийська 3, м. Дрогобич, 82100, e-mail:delenkonadia@mail.ru

Побудовано математичну модель розподілу електростатичного потенціалу в поверхнево-бар'єрній структурі виду Шотткі з вбудованим шаром квантових точок (КТ). Встановлено, що результуюче електричне поле в бар’єрній структурі виду Шотткі з вбудованим шаром КТ визначається суперпозицією двох полів: електричного поля , створеного на межі контакту метал – n-напівпровідник з вбудованим шаром КТ та електричного поля , зумовленого на межі поділу КТ − напівпровідникова матриця з КТ. Показано, що потенціал вздовж напрямку розміщення КТ має осциляційний характер. Період осциляції визначається кроком розміщення КТ. У напрямку, перпендикулярному до межі контакту метал – легований n-типу напівпровідник з КТ, потенціал має спадний експоненційний характер.
Ключові слова: математична модель, рівняння Пуассона.

П. Костробій¹ , Б. Маркович¹, Р. Токарчук1 , Ю. Черноморець², М. Токарчук^2,1

Теоретичні аспекти процесів інтеркаляції: Узагальнені рівняння переносу типу Нернста-Планка для іонів та електронів в системі "електроліт - електрод"

¹Національний університет "Львівська політехніка", вул. Ст. Бандери 12, м. Львів, e-mail:petro.kostrobi@gmail.com
²Інститут фізики конденсованих систем НАН України, вул. Свєнціцького 1, м. Львів, e-mail:yulya@icmp.lviv.ua

Отримано узагальнені рівняння переносу типу Нернста-Планка для іонів та електронів в системі "електроліт - електрод" з використанням метода нерівноважного статистичного оператора. Рівняння переносу враховують ефекти пам’яті в часі та просторову неоднорідність.
Ключові cлова: електроліт, електрод, інтеркаляція, нерівноважний статистичний оператор.

A. Y. Davydok^{1, 2}, O. Y. Chernukha¹, V. Y. Goncharuk^1,3

Simulation of Coupled Thermal and Diffusion Processes Taking Into Account a Substance Decay in a Randomly Nonhomogeneous Stratified Strip

¹ Centre of Mathematical Modelling of Pidstryhach IAPMM of NAS of Ukraine, 15 Dudayev Str., Lviv, 79005, Ukraine, cher@cmm.lviv.ua;
² Pidstryhach Institute for Applied Problems of Mechanics and Mathematics of NAS of Ukraine, 3-b Naukova Str., Lviv, 79060, Ukraine, davydoka@gmail.com;
³ Lviv Polytechnic National University, 12 Bandera Str., Lviv, 79013, Ukraine, vegoncharuk@mail.ru

Processes of thermodiffusion of decaying substance are investigated in a stochastically nonhomogeneous body. The statement of the contact initial-boundary value problem is made with taking into account the ideal contact conditions for temperature and non-ideal ones for concentration. The reference problem is reduced to an equivalent set of integral-differential equations. Its solution is found by the method of successive approximations in the form of Neumann series. The calculating formulae are obtained for the temperature and concentration fields averaged over the ensemble of phase configurations under the condition of the uniform distribution of phases in the body. A software package is developed and on the basis of which a dependence of averaged fields of temperature and concentration on the medium characteristics is investigated. It is shown that the time of the steady-state regime for the temperature is five orders less than for the concentration.
Keywords: simulation, thermodiffusion, decaying substance, Neumann series, averaging over the ensemble of phase configurations, software package.

M.D. Raransky, V.N. Balazyuk, M.I. Melnyk, M.M. Gunko, Ya.S. Verebchan

The Peculiarities of Young's Modulus Surfaces of Cubic Single Crystals Formation

Yu. Fedkovych Chernivtsi National University, 2, Kotsybinsky Str., 50012 Chernivtsi, Ukraine, e–mail: ftt2010@bigmir.net

The analysis of the elastic properties of some metals, semiconductors and alkali halides was carried out. The features of Young's modulus characteristic surfaces formation were revealed. Extreme values of Young's modulus along the main crystallographic directions were determined. The mechanisms of characteristic surfaces formation of Young's modulus were established.

O.P. Malyk¹, H.A. Il’chuk², V.M. Rodych²

The Local Electron Interaction with the Defect Potential in CdTe:Cl Crystals

¹Lviv Polytechnic National University, Semiconductor Electronics Department, 1 St. Yura square, 79013, Lviv, Ukraine
²Lviv Polytechnic National University, Physics Department, 12 Stepan Bandera Str., 79013, Lviv, Ukraine

The processes of the electron scattering on the short-range potential caused by interaction with polar and nonpolar optical phonons, piezoelectric and acoustic phonons, static strain, ionized impurities in Cl-doped CdTe samples with impurity concentration (5×1016 ÷ 5×1017 cm-3 are considered. The temperature dependences of the electron mobility and Hall factor in temperature range 25 ÷ 590 K are calculated.
Keywords: transport phenomena, charge carrier scattering, cadmium tellurium.

I.R. Zachek¹, R.R. Levitsky², O.B. Bilenka¹

Longitudinal Dielectric, Piezoelectric, Elastic and Thermal Properties of CsH2AsO4 Type Ferroelectrics

¹National University ''Lvivska Politechnika'' 12 S. Bandera Str., 79013, Lviv, Ukraine,
²Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011, Lviv, Ukraine

Within the framework of modified model of proton ordering of CsH2AsO4 type ferroelectrics with taking into account linear on strain contribution into the energy of proton system, but without taking into account tunneling within the four particle cluster approximation corresponding thermodynamic potentials are calculated. Using the corresponding equations of state spontaneous polarization are calculated longitudinal dielectric permittivity of a mechanically clamped and mechanically free crystals, their piezoelectric characteristics, elastic constants and molar capacity. At the proper set of parameters good quantitative description of the available experimental data for the CsH2AsO4 type ferroelectrics is obtained. Keywords: ferroelectrics, cluster approximation, dielectric permittivity, piezoelectric modulus, elastic constant.

E.V. Gera¹, O.M. Durkot¹, V.M. Maryan¹, O.A. Mykaylo², M.M. Pop², V.M. Rubish¹, P.P. Shtets¹

Laser Illumination Influence on the Optical Characteristics of As₄₀S_60-xSe_x (0 ≤ x ≤ 15) Films

¹Uzhgorod Scientific-Technological Center of the Institute for Information Recording, NASU, Uzhgorod, Ukraine
²Uzhgorod National University, Uzhgorod, Ukraine

The results of investigation of the As40S60-xSex amorphous films transmission spectra depending on thickness, exposure and heat treatment conditions are given. It was established that the increase of Se content in films composition, illumination and annealing of films leads to the absorption edge shift into the longwave spectral region. The values of pseudogap width Eg and refractive index n are determined. Maximum changes of optical characteristics are found for As40S48Se12 films and take place under laser illumination of high intensity and at short illumination times. Optical characteristic changes of films are caused by photo-thermostructural transformations taking place in them under illumination and annealing.

I.I. Chaviyak

The Influence of Technology Modes on “Hat Wall” Method on Structure and Electrical Properties of SnTe Films

Ivano-Frankivsk National Medical University, 2, Galyzka Str, Ivano-Frankivsk, 76018, Ukraine, Е-mail: freik@pu.if.ua

The results of complex studies of the structure and electrical properties of vapor-phase condensation of SnTe, deposited in the method of "hot wall" on fresh chips of (111) single crystals of BaF2 by various technological factors. The stable p-type conductivity condensates explained by displacement of homogeneity SnTe compound on the side of Tellurium, the value of which depends on the conditions for obtaining.
Keywords: vapor-phase condensates Tin Telluride, structure, defects, electrical properties.

D.M. Freik¹, B.S. Dzundza¹, S.I. Mudryy², O.B. Kostyuk¹, V.I. Makovyshyn¹, R.S. Yavorskyy¹, U.A. Kryskov³, T.O. Semko¹

Structure and Transport Phenomena in films Pb18Ag2-xSbxTe20 (LAST) on Sital Substrate

¹Vasyl Stefanyk Precarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, E-mail:fcss@pu.if.ua
²Ivan Franko National University of Lviv, Kyryla and Mefodiya Str., 8 Lviv, 79005, Ukraine; 3Ivan Ogienko Kam'yanets Podolsky National University 61, Ogienko St., Kam'yanets Podolsky, 32300, Ukraine

Influence of the thickness of thin films based compounds Pb18Ag2-xSbxTe20 (x = 0,5; 1,0; 1,5), deposited on sital substrates from their structure and scattering mechanisms are research. Defined that the dominant role playing scattering on the surface due to the increasing size of nanocrystals with increasing of thickness vapor-phase structures.
Keywords: LAST, scattering mechanisms for charge carriers, mobility, surface, nanostructure.

L.I. Nykyruy¹, I.I. Chaviyak²

The Influence of Thermal Annealing and Radiation Irradiation on substructure of “Hat Wall” SnTe Films

¹Vasyl Stefanyk Precarpathian National University, Shevchenko Str. 57, Ivano-Frankivsk, 76018, Ukraine, е-mail: freik@pu.if.ua,
²Ivano-Frankivsk National Medical University, 2, Galyzka Str, Ivano-Frankivsk, 76000, Ukraine

The results of research of the influence of both the annealing epitaxial SnTe / (111) BaF2 films in vacuum and radiation of ~ 5 MeV alpha particles on their substructure parameters presents in paper.
Keywords: Tin Telluride, structure, thin films.

B.V. Kushnіr¹, Z.R. Kudrinskiy¹, V.M. Kamіnskiy¹, V.V. Homyak²

Topology of Surface of ZnO thin Oxide Film Formed on GaSe Layered Crystal Surface

¹Chernіvetske vіddіlennya Іnstitutu problems materіaloznavstva IM. I. M. Frantsevich NAS of Ukraine, Vul. I. Vіlde, 5, Chernivtsi, 58001, E-mail:chimsp@ukrpost.ua
²Chernіvetsky natsіonalny unіversitet IM. Fedkovych, Vul. Kotsyubinskogo, 2, Chernivtsi, 58000

Heterostructure n-ZnO ( p-GaSe was prepared by the magnetron sputtering method. Topology of surface of ZnO thin oxide film formed on freshly cleaved surface of GaSe layered crystal was investigated; sensitivity spectral areas was identified. It is shown that the ZnO film has a hexagonal structure. The method of AFM images has revealed that ZnO thin oxide film has a granular structure; numerous channels indicating the complex nature of the substrate wetting zinc oxide were identified.
Keywords: gallium selenide, ZnO, thin film, heterojunction, AFM images.

D.M. Freik¹, Ya.S. Yavorskyy¹, I.I. Chav'yak², V.I. Makovyshyn¹, O.M. Matkivskyi¹ R.Ya Yaremkiv²

Structure and Thermoelectric Properties of Doped Bismuth Telluride Vapor-Phase Condensation Tin SnTe: Bi

1Vasyl Stefanyk Precarpathian National University 57, Shevchenko Str., 76018, Ivano-Frankivsk, Ukraine, E-mail:freik@pu.if.ua
2Ivano-Frankivsk National Medical University, 2, Galyzka Str, Ivano-Frankivsk, 76018, Ukraine, Е-mail: freik@pu.if.ua

The results of a comprehensive study of the phase composition, structure and thermoelectric properties of doped bismuth (0,3 2 at.% Bi) thin films SnTe: Bi, deposited on the high vacuum for fresh chips (0001) single crystals of muscovite mica. The mechanisms of nucleation and growth processes, and depending on the size of nanocrystals and electrical parameters on the thickness of the condensate and content of Bi dopant. Found that the optimal thermoelectric properties of thin films SnTe: Bi defined as the thickness and dopant content. The results are presented physico-chemical treatment. Keywords: thin films, nanostructures, doping, Tin Telluride.

D.М. Freik¹, L.V. Turovska², I.V. Horichok¹, O.M. Matkivskyi¹

Crystal-Chemical Interpretation of Amphoteric Influence of Bismuth Impurity in Tin Telluride

¹Department of Physics and Chemistry of Solid State at the Vasyl Stefanyk PreCarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, e- mail: freik@pu.if.ua; ²Department of Medical Informatics, Medical and Biological Physics at Ivano-Frankivsk National Medical University, 2, Halytska Str., Ivano-Frankivsk, 76018, Ukraine, e-mail: lturovska@gmail.com

Models of point defects of doped by bismuth tin telluride crystals considering amphoteric influence of dopant ( ) have been specified. The influence of disproportionation of charge state of impurity on the conductivity type has been determined. Based on the proposed crystal-quasichemical formulae dependences of concentrations of point defects, the Hall concentration of current carriers on dopant content have been calculated.

O.A. Sivak, M.I. Cherednyk, I.M. Totskiy, A.Yu. Popov, V.A. Makara

The Peculiarities of Refractory Phases in the System Al-Сr₂О₃-B₂O₃

Taras Shevchenko National University of Kyiv, Ukraine, e-mail:decanat_phys@univ.kiev.ua

In this paper we investigated the temperature and time dependence of Education refractory Al2O3 phases during the synthesis reaction at temperatures of isothermal holding from 1000°C to 1600°C and a duration of 2 to 16 minutes. It is shown that the synthesis reaction of Al-Cr2O3 and Al-B2O3 occurs in several stages and leads to the formation of additional, on fusible phases such as B2O3, chromium metal and aluminum and chromium yntermetalidiv that at a high temperature sintering decay modes to form refractory compounds. Using the reaction mixture Al-Cr2O3 -B2O3 ( energy yield of the reaction is 730 kJ, allowing at temperatures from 1300°C to obtain formulations contain only refractory ceramic phase.
Keywords: boron oxide, aluminum oxide, chromium oxide, reaction synthesis, refractory phase.

D.M. Freik, M.P. Levkun, V.M. Boychuk, G.Ya. Gurgula, L.D. Yurchyshyn

Crystal Defect Analysis Subsystem Alloyed and Annealed in a Layer of Selenium Crystals ZnSe:Mn

Carpathian National University named after V. Stefanik st. Shevchenko, 57, Ivano-Frankivsk, 76000, Ukraine, e-mail:fcss@pu.if.ua

Based on the proposed formulas for Crystal Doped Magnesium of n-ZnSe: Mn and p-ZnSe: Mn is calculated depending on the prevailing concentration of point defects, free-carrier concentration and Hall on the content of dopant Mn. Confirmed donor effect of manganese. It is shown that annealing of n-ZnSe: Mn in a couple of Se leads to a decrease in the concentration of electrons in crystals and p-ZnSe: Mn has been an increase in the major carriers.

T.R. Tatarchuk, E.V. Boyko, I.P.Yaremiy, B.І. Rachiy, S.V. Fedorchenko

Synthesis, Crystal Chemistry and Antistructure Modelling of CoFe2O4 Nanoparticles Prepared by Citrate Sol-Gel Method

Vasyl Stefanyk Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine Tel. (0342) 59-61-62; (050) 086.73.45, e-mail:tatar_ch@inbox.ru

Cobalt ferrite nanoparticles were synthesized by the citrate sol-gel method and characterized by XRD, FT-IR, TG-DSC techniques. X-ray analysis confirms the formation of single phase cubic partially inverse spinel structure with the average particle size of 37 nm. Distribution of cations among the two interstitial sites (tetrahedral and octahedral sites) has been estimated by analyzing the powder X-ray diffraction pattern by employing Rietveld refinement technique. The FT-IR study between 4000 and 370 cm-1 shows two absorption bands corresponding to tetrahedral and octahedral sites of CoFe2O4 spinel structure. Crystalloquasichemical model of formation СoO and Fe2O3 defects phases and their interactions was described.
Keywords: cobalt ferrite, spinel, sol-gel method, auto combustion, defect.

L.S. Dzubenko¹, O.O. Sapyanenko¹, P.P. Gorbyk¹, I.O. Tsebrenko², N.M. Rezanova², I.A. Mel’nyk²

The Influence of Nanodispersed Silver/Alumina Addition on the Rheological Properties of Melts and Phase Transitions in Polypropylene/Copolyamide Blends

¹O.O.Chuiko Institute for Surface Chemistry of NAS of Ukraine, 17, Generala Naumova Str., 03164, Kyiv-164; e-mail:ryash@i.ua,
²Kyiv National Univercity for Technologies and Design, 2, Nemyrovycha-Danchenko Str., 01011, Kyiv-11, e-mail:mfibers@ukr.net

There is concentration influence of nanodispersed silver/alumina addition combined on appropriatenesses of polypropylene/copoliamide mixture melt flow studied. There are dependences of swelling and viscosity from Ag/Al2O3 concentration of extremal nature: the minimal viscosity and maximal elasticity are characteristic both for blend, containing 0.05% mass. of addition. It is shown, using DTA technique, that addition in low temperature range having positive influence on crystal structure forming of composite extrudates. It is founded, that silver in initial position distributed, mainly, in the cluster and nanoparticles (up to 20 nm) forms, and, mainly, in the extrudates of treble blends, as nanoparticle form. Mainly, the silver in polypropylene microfibers removed from treble extrudates, in cluster form founded. There is presence of silver in polypropylene microfibers, which is important for creation of bactericidal thin-fibrous filters.
Keywords: polypropylene/copolyamide blend; polypropylene/copolyamide mixture; nanodisperse addition; silver; alumina; extrudates; polypropylene microfibers.

L.M. Boichyshyn, O.M. Hertsyk, M.O. Kovbuz, T.G. Pereverzeva, S.I. Mudryi, B.Ya. Kotur

Electrochemical Synthesis of Surface Oxide Layers on the Amorphous Metallic Alloys Fe-Nb-B-REM

Ivan Franko National University of L’viv, Kirila and Mephodia Str. 6, UA-79005 L’viv, Ukraine, e-mail:o_hertsyk@yahoo.com

Electrochemical characteristics of the amorphous metallic electrodes Fe-Nb-B-REM with oxide-hydroxide layers have been obtained by voltamperometric investigation. During the process has been used regular saturation of KOH solution by oxygen for forming passive surface layers and also has been optimized temperature of the reaction environment. We got by both methods stable oxygencontaining passive layers nonsoluble in 5 M aqueous solution at 313 K and repeated cyclic polarization.
Keywords: amorphous alloys based on Fe, rare earth metals, x-ray energy-dispersing microanalysis, metallic hydroxooxides.

V.A. Pylypchenko¹, G.V. Vasileva¹, I.I. Haysak¹, V.I. Yakovlev², Yu.M. Kylivnyk², M.M. Tsyba²

Research Sorption of Barium and Strontium Inorganic Sorbents and Opportunity Elemental Surface Analysis Methods Sorbents Photonuclear

¹Uzhhorod National University, Uzhgorod, Ukraine e-mail:hvvasylyeva@hotmail.com
²Instytut sorption and problems endoecology, Kyiv, Ukraine,

Sorption of Ва2+ and Sr2+ ions from aqueous solutions by titanium phosphate and pelleted zirconium silicate is studied. Efficiency of zirconium silicate for Ва2+ ion extraction is shown. The parameters of the porous structure of the sorbents under investigation were determined by low-temperature adsorption–desorption of nitrogen. The presence of barium sorbed by titanium phosphate is qualitatively determined by photonuclear technique using Brehmsstrahlen gamma-rays with energies below 25 MeV for the excitation.
Keywords: inorganic sorbents, porous size, Brehmsstrahlen gamma-rays, barium and strontium ions.

G.V. Snizhnoi¹, S.V. Bobyr²

Magnetic State of Austenitic Steel X8CrNiMnNb2092 after Cryogenic Treatment

1Zaporozhye National Technical University, ul. Zhukovskogo 64, Zaporozhye, 69063, Ukraine, e-mail:snow@zntu.edu.ua
2Institute of Ferrous Metallurgy NAS of Ukraine, pl. acad. Starodubova 1, Dnepropetrovsk, 49050, Ukraine

The specific magnetic susceptibility (0 paramagnetic austenite chromium-nickel steel 0 X8CrNiMnNb2092 experimentally found. The value of (0 degree of magnetic state and susceptibility to martensitic transformation of austenitic chromium-nickel steel describes. The relationship between the amount of formed martensite deformation and changes in specific magnetic susceptibility (0 austenite determined. Effect of cryogenic treatment on the value of (0 austenite detected.

А.В. Мініцький

Розробка композиційних порошкових матеріалів електротехнічного призначення

НТУУ «КПІ», пр. Перемоги,37, Київ, 03056, Україна, тел. 4549904, e–mail: minitsky@i.ua

Робота присвячена розробці порошкових магнітно-м’яких матеріалів на основі композиційних залізних порошків для роботи в постійних та змінних полях промислової частоти. На основі результатів досліджень обґрунтовано і експериментально підтверджена ефективність використання для одержання спечених магнітно-м’яких матеріалів з підвищеним рівнем магнітних характеристик порошків заліза плакованих нікель-фосфором, оловом та фосфором.
Ключові слова: магнітно-м’які матеріали, плакований порошок.

H.O. Sirenko, L.M. Soltys, I.V. Sulyma

Correlation of Antiwear and Antifriction Properties of Carbon Fiber with Hardness and Roughness of Metal Adjacent Surfaces

Vasyl Stefanyk Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine, e-mail:orijant@gmail.com

Correlations between friction coefficient and intensity of wear of polytetrafluoroethylene – carbon-plastic, derived by CMA-technology, and nature, hardness, roughness (initial and the one that arose in the friction and wear), changes of roughness of adjacent surface, the way of friction etc in the friction tests at constant tempera¬ture and ultrahigh and high specific loads (at normal load of 40 - 100 N for one sample) have been detected.
Keywords: roughness, intensity of wear, friction, composite polymer material, metal adjacent surfaces, specific loads, correlation.

A.B. Lysenko, O.L. Kosynska, G.V. Borisova, A.A. Kazantseva

Model of Mass Crystallization in Layers of Small Thickness

Dneprodzerzhinsk State Technical University, Dneprodzerzhinsk, Dneprostroevskaya st. 2, 51918, Ukraine, e-mail:ablysenko@ukr.net

The model of mass crystallization, which allows to take into account the blocking effect of the growing crystals by surfaces of thin layers of melt or rapidly quenched amorphous ribbons is proposed. The kinetic equations describing the contributions to the transformed volume fraction of the crystals which nucleate at considerable distances from the surfaces and maintain the initial spherical shape during whole solidification period, and those formed in the near-surface (critical) areas and undergoing the blocking effect of surfaces which results in the truncated sphere shape are derived. The analysis of the limiting versions of the model is performed. It is shown that using of the developed approach leads to reducing of the calculated values of the crystallized volume fraction up to 25%.
Keywords: mass crystallization, thin layers, blocking crystals by surfaces, reducing of the transformed volume fraction.

H.O. Sirenko, L.M. Soltys

Tribosurface Properties of Polymer Composite in Friction and Wear on Anisotropic Rough Surface of Steel 45

Vasyl Stefanyk’ Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine, e-mail:orijant@gmail.com

Regularities of change of anisotropic roughness surfaces of steel 45 in friction and wear in a pair with polymer composite has been researched. It has been detected that the topography of the conjugated metal surface with polymer composite is the dominant factor in determining the value of wear of carbon-plastics at both the start and in the process friction and wear when the metal surface roughness is created by the composite. It has been established that the invariant combinations of zero-order moments in greater degree linearly influences on wear of the polymer sample than invariant combinations of second-order moments, and the wear nonlinearly depends from invariant combinations of fourth-order moments.
Keywords: roughness, intensity of wear, anisotropic surface, friction, composite polymer material, moments of spectral density, minorant rows.

О.С. Завойко

Дослідження лазерного зміцнення колінчатих валів та механо-термічної обробки при руйнуванні на втому та знос

Чернівецьке відділення, Національний Технічний Університет "Харківський Політехнічний Інститут", вул. Головна, 204, м. Чернівці, Україна

Досліджено новий спосіб фізико-технічної обробки та зміцнення поверхонь за допомогою комбінування трьох технологічних процесів – лазерної, фізико-термічної та поверхнево-пластичної механічної обробок. Вивчення і впровадження фізичних процесів лазерної взаємодії із високо вуглецевими стальними деталями відкриває нові можливості їх застосування у машинобудуванні та створенні нових технологічних комбінованих процесів виробництва деталей машин. Розглядається вплив лазерної обробки та послідуючих термообробок на структуру, мікротвердість, шорсткість поверхні, остаточних напружень, зносостійкість під впливом абразиву і терті ковзанням, а також опір втомного руйнування високоміцного чавуна ВЧ60-2 з метою розробки технології лазерного зміцнення колінчатих валів тепловозів та подібних валів вантажних автомобілів.
Ключові слова: комбінована фізико-технічна обробка, лазерна обробка, поверхнево-пластична механічна обробка, фізико-хімічна термічна обробка.

P.O. Gentsar, O.I. Vlasenko , S.M. Levytskyi, V.A. Gnatyuk

Laser-Stimulated Increase Reflectivity of Semiconductors

V. Lashkoryov Institute of Semiconductors Physics, prospect Nauki, 41, Kyiv, 03028, e-mail: rastneg@isp.kiev.ua

In this paper presents the results of optical reflection spectra of single crystals of n-Si (100) and CdTe (111) in the range 0.2 1.7 microns before and after laser irradiation in the range of energies 66 164 mJ/cm2. Is experimentally shown to increase reflectivity of the studieds crystals at a given laser irradiation. This cumulative effect is explained by differences in the optical characteristics of the surface layer and volume of the material (complex refractive index of the surface layer is different from the complex refractive index of volume of the material ). Examined the mechanisms of laser irradiation. Calculated depending on the depth of the formation of a shock wave, surface temperature, depth of melting Si and CdTe during laser irradiation.
Keywords: Si, CdTe, laser irradiation, reflectance spectrum, shock wave, the surface temperature, depth of melting.

O.O. Gavrylyuk, O.Yu. Semchuk

Distribution of Temperature Profiles in Nonstoichiometric SiOx Films by Laser Annealing of the Two Beams

Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine 17 General Naumov Str., Kyiv, 03164, Ukraine, e-mail:oleksandr_gavrylyuk@mail.ru

Theoretical study of temperature distribution profiles in nonstoichiometric SiOx films by annealing two laser beams of equal intensity. Temperature distribution on the surface of the films SiOx, irradiated laser beams at different distance from each other are calculated.It is shown that laser annealing with the intensity of the laser beam 59 MW/m2, the temperature on the surface of the SiOx films can reach 1800K. The temperature at the surface of the sample between the lasers is insufficient to generate a phase transition in nanocomposite film SiOx film SiO2 (Si) of silicon nanocrystals. Silicon nanoparticles formed precisely positions the peak intensity of the laser radiation.
Keywords: nonstoichiometric films, thermal conductivity, nanocrystals, nanocrystal, laser annealing.

E. Ph. Shtapenko, V.A. Zabludovsky, V.V. Dudkina

Surface Diffusion at Electrocrystallisation

Dnepropetrovsk national university of railway transport

Surface diffusion of ad-atoms of nickel, copper and iron on its own substrates at electrocrystallisation was investigated. With the help of quantum-mechanical approach the activation energies for the two directions of hopping at different potentials of the substrate. The activation energy for surface diffusion is determined as the difference between the total energy of the crystal with the ad-atom in the equilibrium adsorption state in which energy is minimal and in the transition point of the saddle. It is shown that an increase in the surface potential is an increase in the activation energy of surface diffusion.
Keywords: surface diffusion activation energy, the total energy of the crystal, ad-atom quantum-mechanical approach.

S.P. Novosyadlyy, S.M. Marchuk, V.M. Varvaruk, L.V. Melnyk

Models Semiinsulating Layers of Gallium Arsenide in Their Formation of Multiply Charged Ion Implantation

Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, E-mail:fcss@pu.if.ua

The technology multiply implantation of impurities, which allow lateral and vertical insulating layers. Experimental study on the creation of high-and thermostable insulating layers in ion-doped n +-n - i-semiinsulating structures on GaAs.
Keywords: gallium arsenide technology, multiply implantation, background impurities.

Z.D. Kovalyuk¹, I.P. Mykytyuk¹, N.S. Yurtsenyuk², and S.P. Yurtsenyuk¹

A Porous Carbon Material of Organic Raw Materials of Vegetable Nature as an Electrode Component for Electric Double-Layer Capacitors

¹Chernivtsi Department of the Institute of Materials Science Problems of the National Academy of Sciences of Ukraine, Iryna Vilde St., 5, Chernivtsi, 58001, Ukrainе
²Yu.Fed’kovych Chernivtsi National University, Kotsyubyn’sky St., 2. Chernivtsi, 58012, Ukraine

In this paper we present investigations of nanoporous carbon materials from organic raw materials of vegetable nature appropriate to be used as an electrode component in supercapacitors with an aqueous electrolyte. For such materials the principal energy - capacity characteristics are determined. Some types of supercapacitors based on the obtained materials are developed and their parameters are investigated.
Keywords: vegetable raw material, supercapacitor, electrode, capacity.

I.M. Kas’yanenko, V.Yu. Kramarenko

Relationship Between Contact Angle and Sliding Angle of Drop on Inclined Surface

National technical university – “Kharkiv state polytechnical institute” 21, Frunze Str., 61002, Kharkiv, Ukraine, e-mail:kram.cap@gmail.com

The Frenkel’s task for relationship of equilibrium contact angle and sliding angle of drops on inclined surfaces has been considered. A linear dependency of inverse sinus of sliding angle and mass of the drop in power 2/3 has been established. A tangent of this dependency could be presented as product of two constants, one of which is characterized by liquid physical coefficients and other is characterized by a trigonometric function of equilibrium contact angle. Capabilities of modeling drops behavior on inclined surfaces based on proposed approach have been shown.
Keywords: surface properties, contact angle, hydrophobicity.