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1
Content available remote The influence of Kanthal wire surface defects on the formation of Si nanolayer deposited by PVD method
Szczypiński M., Reszka K., Szczypiński M. M.
Materials Science Poland
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2018
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Vol. 36, No. 2
264--269
EN
The subject of this research is the structure of a Si nanolayer deposited on a FeCrAl wire surface by means of magnetron sputtering method. Si layer was selected as one of possible protections of the wire surface against excessive corrosive-erosive wear. In order to increase the power necessary for the DC discharge of the magnetron with Si cathode, a second magnetron with an aluminum disc as a cathode was used. The wire was attached to a carousel holder to ensure its rotation around the magnetron. The thickness of the deposited layers was about 150 nm. A wire surface examination indicated the presence of defects such as gaps between grains, cavities as well as severely deformed grains of surface layer. The research was conducted on the sample sections which had been prepared by focused ion beam method (FIB). The technique of transmission microscopy, which was used for observation, allowed us to obtain images in bright field (BF), dark field (DF), as well as in high resolution (HREM). The studies were also performed on the wire surface after the cutting process of the expanded polystyrene blocks. A metallographic optical microscope Nikon MA200 with a large depth of field was used for the examination which showed the presence of carbon deposit products. Additionally, a composition microanalysis was carried out along the line within selected areas of samples, with the use of energy dispersive spectroscopy (EDS). A large impact of wire surface defects on Si layer forming was found as well as a high direct homogeneous growth. The examination of the sections indicated the existence of a mechanism of defects sealed by Si layer, where directionality of grains growth in these areas revealed the tendency for vertical location relative to defects surface. Consequently, closed nanopores, i.e. spaces not covered with Si layer, were created. It is a characteristic feature of areas with defects covered with an oxide film created in a natural way.
2
Content available Application of chemical pre-treatment on the polished surface of aluminium alloys
Kraus P., Svobodova J., Cais J., Lattner R.
Advances in Science and Technology. Research Journal
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2016
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Vol. 10, nr 32
17--23
EN
This paper reports the preparation and characterization of thin transparent nanolayers with phase composition ZrF4 and different modification of SiO2 with special focus on affecting the surface roughness of the material and the way of exclusion of the thin nanolayer on the surface of the polished aluminium material. The thin nanolayer was prepared by the sol-gel method. The final treatment based on PTFE was applied on the surface of some samples. This treatment is suitable for increasing wear resistance. The films were characterized with help of SEM microscopy and EDS analysis. The surface roughness was measured with classical surface roughness tester. The results on this theme have already published but not on the polished surface of the aluminium material. The results from the experiment show the problems with application of these nanolayers because a cracks were found on the surface of the material and deformations of the layer after application of the PTFE final layer. The surface layer formation is discussed.
3
Content available remote Numerical model of the nanoindentation test based on the digital material representation of the Ti/TiN multilayers
Perzyński K., Wiatr R., Madej Ł.
Materials Science Poland
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2015
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Vol. 33, No. 2
348--355
EN
The developed numerical model of a local nanoindentation test, based on the digital material representation (DMR) concept, has been presented within the paper. First, an efficient algorithm describing the pulsed laser deposition (PLD) process was proposed to realistically recreate the specific morphology of a nanolayered material in an explicit manner. The nanolayered Ti/TiN composite was selected for the investigation. Details of the developed cellular automata model of the PLD process were presented and discussed. Then, the Ti/TiN DMR was incorporated into the finite element software and numerical model of the nanoindentation test was established. Finally, examples of obtained results presenting capabilities of the proposed approach were highlighted.
4
Content available remote Computations of RHEED intensities for growing surfaces of GaAs
Mitura Z.
Computer Methods in Materials Science
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2015
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Vol. 15, No.4
447--458
EN
A novel and practical algorithm for the determination of intensities in reflection high-energy electron diffraction RHEED) for off-symmetry azimuths is presented. The usefulness of the algorithm is demonstrated for calculations of rocking curves for GaAs. Then the problem of RHEED oscillations that appear during regular growth of nanolayers is discussed. A calculated plot of the oscillation phase is compared with experimental data taken from the literature. Only :he unreconstructed surface of GaAs is considered in this analysis, however, even for such a simplified case, the plot of the theoretical phase reproduces the experimental results reasonably well.
PL
Zaprezentowano nowy, praktyczny algorytm komputerowy do wyznaczania natężeń wiązki zwierciadlanej dla dyfrakcji odbiciowej elektronów wysokoenergetycznych (zakłada się, że padająca wiązka elektronów nie pokrywa się z kierunkami osi symetrii powierzchni kryształu). Użyteczność algorytmu zademonstrowano w obliczeniach krzywych odbicia dla arsenku galu. Następnie omówiono zagadnienie charakterystycznych oscylacji natężenia wiązki odbitej zwierciadlanie, które pojawiają się, gdy wzrost warstw nanostrukturalnych odbywa się w sposób bardzo regularny. W szczególności przeprowadzono porównanie literaturowego wykresu fazy oscylacji uzyskanego na podstawie pomiarów z wykresem sporządzonym na podstawie obliczeń. Uzyskano dobrą zgodność wyników eksperymentalnych i teoretycznych, chociaż w pracy rozważano tylko najprostszy model powierzchni kryształu arsenku galu.
5
Content available Numerical modeling of fracture during nanoindentation of the TiN coatings obtained with the PLD process
Perzyński K., Madej Ł.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2013
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Vol. 61, nr 4
973--978
EN
In order to improve mechanical, frictional or biocompatibility behavior of well know materials like titanium (Ti) or titanium nitride (TiN) scientists are trying to develop new manufacturing and processing operations. One of those methods, that provide interesting results, is called deposition process. During deposition a material is upgraded with new surface layers that are characterized by specific required properties. These layers have usually different mechanical properties in comparison with a substrate material. A combination of different properties of the deposited layers can significantly change behavior of the structure under an exploitation condition. However, layers have usually nanometer scale, which causes problems with performing standard plastometric tests. One of the possibilities to solve this issue is an application of specially designed tests like nanoindentation. Nanoindentation can provide valuable information regarding mechanical and strength behavior of nanostructure components. These investigations are of importance to properly identify and design properties of the mentioned deposited materials. Unfortunately, experimental analyses at these scales are usually very expensive. That is why Authors decided to develop a numerical model of the nanoindentation test to investigate material behavior under loading conditions that can support experimental research. The overall aim of this research is development of a failure model, which can take into account morphology of microstructure of ceramic TiN layer deposited on the silicon substrate. Modeling of crack behavior was realized on the basis of the extended finite element method (XFEM).
6
Teoretyczna analiza adsorpcji tlenu na powierzchni ziaren SnO₂ o powierzchni płaskiej
Izydorczyk W.
Elektronika : konstrukcje, technologie, zastosowania
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2009
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Vol. 50, nr 10
45-48
PL
W pracy przedstawiono wyniki teoretycznej analizy wpływu adsorpcji tlenu na przewodnictwo nanowarstw SnO₂. W wyniku analitycznego rozwiązania jednowymiarowego równania Poissona-Boltzmanna dla próbki o skończonych wymiarach i płaskiej geometrii ziarna, otrzymano potencjał powierzchniowy dla całkowicie zubożonych warstw o grubości w zakresie 30..,500 nm. Na tej podstawie obliczono zależność energetycznej bariery potencjału od grubości warstwy. Zbadano wpływ ruchliwości oraz stopnia jonizacji donorów na stopień pokrycia powierzchni różnymi jonami tlenu. Obliczono profile głębokościowe koncentracji nośników, rozkład ruchliwych donorów oraz zbadano wpływ temperatury oraz ciśnienia cząstkowego tlenu na konduktancję nanowarstw SnO₂.
EN
In this work, the results of theoretical analysis of the influence of surface oxidation on the conductance of SnO₂ nanofilms were presented. From the one-dimensional analytical solution of the Poisson-Boltzmann equation in the case of finite grains with slab geometry, the in-depth profiles of the potential V(r) were obtained for full depleted layers. On this basis, the surface energy barrier dependence on grain size (30...500 nm) was obtained. The effect of the donor mobility (oxygen vacancies in the bulk) and degree of donor ionization on coverages by oxygen ions was discussed. The in-depth profiles of carrier concentrations and distribution of donors were obtained. Furthermore, the influence of temperature and partial oxygen pressure on the SnO₂ nano-film per-square conductance was studied.
7
Content available remote Computer analysis of oxygen adsorption at SnO2 thin films
Izydorczyk W., Adamowicz B.
Optica Applicata
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2007
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Vol. 37, nr 4
377-385
EN
An influence of oxidation of SnO2 thin films on depletion layer electronic parameters and film conductance has been studied by means of computer simulations. The surface potential value and in-depth potential profiles in the depletion region have been obtained by solving the Poisson--Boltzmann equation in the case of grains with slab geometry and different doping. The SnO2 grain thickness was in the range from 20 to 500 nm. The surface coverage by oxygen ions (O2-, O-) as well as film conductance per square and its sensitivity versus temperature (from 300 to 900 K) have been rigorously calculated. The effect of donor (oxygen vacancies) mobility and degree of donor ionisation has been taken into account.
8
Content available remote Thermogravimetric Measurements of Poly(Propylene) Nonwovens Containing Deposited Layers of Polyelectrolytes and Colloidal Particles of Noble Metals
Połowiński S., Stawski D.
Fibres & Textiles in Eastern Europe
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2007
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Vol. 15, no. 4 (63)
82--85
EN
The layer-by-layer method was used as a convenient way for depositing colloidal particles of silver, gold or platinum on textiles. After modifications the samples were tested using thermogravimetric analysis. It was found that the incorporation of metal particles onto a poly(propylene) nonwoven surface significantly increases thermal resistance. In the work herein presented it is proved that a significant increase in thermal resistance is observed when hydrogen saturated colloidal platinum has been incorporated.
PL
Metoda „ warstwa-po-warstwie” została zastosowana w celu nanoszenia koloidalnych czastek srebra, złota i platyny na wyroby tekstylne. Po modyfikacji, próbki analizowano metodą termograwimetryczną. Stwierdzono, ze wprowadzenie cząstek metali na powierzchnię włókniny polipropylenowej znacząco podwyższa odporność termiczną. W pracy stwierdzono, że wysycenie wodorem koloidalnej platyny naniesionej na włókninę powoduje wyjątkowo duży wzrost odporności termicznej.
9
Content available remote Optical investigations concerning layered metalphthalocyanine nanostructures affected by NO2
Pustelny T., Ignac-Nowicka J., Jarząbek B., Burian A.
Optica Applicata
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2004
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Vol. 34, nr 4
551-561
EN
The paper deals with investigations concerning the coefficient of optical transmission of selected metalphthalocyanine layers, viz. CuPc, NiPc, PbPc and CoPc by means of optical spectroscopy. The coefficient of transmission was investigated for phthalocyanine layers in the presence of atmospheric air and after the exposition of these layers to 100 ppm nitrogen dioxide. These investigations concerned wavelengths in the range from about 300 to 1300 nm. Moreover, several phthalocyanine layers were measured in the air and at 100 ppm NO2 applying the X-ray diffraction method. These investigations have made it possible todetermine changes occurring in the structure of phthalocyanine exposed to nitrogen dioxide.
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