Growth and Characterisation of Pulsed-Laser Deposited Tin Thin Films on Cube-Textured Copper at Different Temperatures

High-quality titanium nitride thin films have been grown on a cube-textured copper surface via pulsed laser deposition. The growth of TiN thin films has been very sensitive to pre-treatment procedure and substrate temperature. It is difficult to grow heteroexpitaxial TiN films directly on copper tape due to large differences in lattice constants, thermal expansion coefficients of the two materials as well as polycrystalline structure of substrate. The X-Ray diffraction measurement revealed presence of high peaks belonged to TiN(200) and TiN(111) thin films, depending on used etcher of copper surface. The electron diffraction patterns of TiN(200)/Cu films confirmed the single-crystal nature of the films with cube-on-cube epitaxy. The high-resolution microscopy on our films revealed sharp interfaces between copper and titanium nitride with no presence of interfacial reaction

Numeryczna i doświadczalna analiza pękania atrombogennych powłok nanoszonych na komory wspomagania pracy serca w próbie mikrościnania

The Polish left ventricular assist device (LVAD – RELIGA_EXT) will be made of thermoplastic polycarbonate-urethane (Bionate II) with deposited athrombogenic nano-coatings: gold (Au) and titanium nitride (TiN). Referring to the physical model, the two-scale model of LVAD developed in the previous works in the authors’ finite element code is composed of a macro-model of blood chamber and a micro-model of wall: TiN, Au and Bionate II. The numerical analysis of stress and strain states confirmed the possibility of fracture based on localization of zones of the biggest values of triaxiality factor. The introduction of Au interlayer between TiN and polymer improved the toughness of the connection, and increased the compressive residual stress in the coating what resulted in reduction of stress and strain close to the boundary between substrate and coating. However, the proper design of multilayer wall of the medical device requires the introduction of the real stress and strain states in the deposited coatings. The characteristics of TiN nano-coating such as residual stress, material model and fracture model were determined in the previously completed studies such as experimental and numercial nanoindentation tests, profilometry studies and in situ SEM’s micro-tension tests. The experimental in situ SEM’s micro-shear test was performed in the present paper and the corresponding numerical model of the test was also developed, and then, interpreted. The critical strains taken from experiment and considered as the effective strains in the model of test are the values which are the function of triaxiality factors for the tested samples. The developed in the authors’ FE code model of multilayer wall of VAD enriched with critical strain determined in the present paper enables prediction of fracture.Polska lewa komora wspomagania pracy serca (LVAD – RELIGA_EXT) zostanie wykonana z termoplastycznego poliwęglano-uretanu (Bionate II) z naniesionymi atrombogennymi powłokami: złota (Au) i azotku tytanu (TiN). W odniesieniu do modelu fizycznego, dwuskalowy model komory LVAD opracowany we wcześniejszych pracach w autorskim kodzie elementów skończonch jest złożony z modelu makro czaszy krwistej i z mikro-modelu ściany: TiN, Au i Bionate II. Analiza numeryczna stanów naprężenia i odkształcenia potwierdziła prawdopodobieństwo pękania poprzez zlokalizowanie stref o największej wartości współczynnika naprężenia trójosiowego. Wprowadzenie międzywarstwy złota pomiędzy TiN i polimer poprawiło wytrzymałość tego połączenia i powiększyło ściskające naprężenie własne w powłoce, co doprowadziło do redukcji naprężenia i odkształcenia blisko granicy pomiędzy podłożem i powłoką. Jednakże, właściwy projekt wielowarstwowej ściany urządzenia medycznego wymaga wprowadzenia rzeczywistych stanów naprężeń i odkształceń w naniesionych powłokach. Charakterystyki powłok TiN takie jak naprężenie własne, model materiału i model pękania zostały określone we wcześniej wykonanych badaniach takich jak doświadczalne i numeryczne testy nanoindentacji, badania profilometryczne, i testy mikrorozciągania prowadzone pod elektronowym mikroskopem skaningowym. W niniejszej pracy przeprowadzono doświadczalny test mikrościnania pod skaningowym mikroskopem elektronowym, opracowano model numeryczny tego testu, a następnie go zinterpretowano. Odkształcenia krytyczne otrzymane z doświadczenia i określone w modelu testu jako intensywność odkształcenia są wartościami będącymi funkcją współczynników naprężeń trójosiowych dla badanych próbek. Opracowany w kodzie własnym model elementów skończonych wielowarstwowej ściany komory VAD wzbogacony o określone w niniejszej pracy odkształcenia krytyczne umożliwia przewidywanie pękania

Growth and Characterisation of Pulsed-Laser Deposited Tin Thin Films on Cube-Textured Copper at Different Temperatures

High-quality titanium nitride thin films have been grown on a cube-textured copper surface via pulsed laser deposition. The growth of TiN thin films has been very sensitive to pre-treatment procedure and substrate temperature. It is difficult to grow heteroexpitaxial TiN films directly on copper tape due to large differences in lattice constants, thermal expansion coefficients of the two materials as well as polycrystalline structure of substrate. The X-Ray diffraction measurement revealed presence of high peaks belonged to TiN(200) and TiN(111) thin films, depending on used etcher of copper surface. The electron diffraction patterns of TiN(200)/Cu films confirmed the single-crystal nature of the films with cube-on-cube epitaxy. The high-resolution microscopy on our films revealed sharp interfaces between copper and titanium nitride with no presence of interfacial reaction

Chemical, Magnetic and X-Ray Diffraction Studies of the Sediments from Oil Field in Argentina

Chemical, magnetic, and phase composition analysis of deposits taken from sedimentation tank from oil plant in Argentina was carried out. Energy dispersive spectroscopy indicates iron as a main sediment component with the site dependent fraction ranging from 11% to 78% (weight percentage). Moreover, large fractions of sulfur (4%-33%), oxygen (8%-28%), calcium (1%-14%), and silicon (1%-11%) were found. The chemical analysis performed with wet chemical methods also indicated Fe as a main component (about 35%), additionally a large fraction ( ≈ 15%) of the sulfur and under 10% fractions of calcium ( ≈ 7%), carbon ( ≈ 6%), and silicon ( ≈ 5%) were found in the sample. The phase composition studies performed using X-ray diffraction showed magnetite - $Fe_3O_4$, goethite - α-FeOOH, lepidocrocite - γ-FeOOH, siderite - $FeCO_3$, and iron-sulfur compounds (mackinawite - FeS, stoichiometric FeS, greigite - $Fe_3S_4$) and other compounds like aragonite - $CaCO_3$, calcite - $CaCO_3$, anorthite - $CaAl_2Si_2O_8$, quartz - $SiO_2$ and barium sulphate $Ba(SO_3)_{0.3}(SO_4)_{0.7}$. Studies performed by the Mössbauer spectroscopy, confirmed presence of majority of compounds identified by X-ray diffraction. Magnetic AC susceptibility measurements show that magnetite is a main component of the studied deposit. High concentration of the magnetic compounds deposited in the sedimentation tank points to the advisability to install the magnetic device designed to support water treatment processes, i.e.: flocculation, coagulation, sedimentation, and filtration. This device could simultaneously inhibit microbiological and chemical corrosion

Nanostructured Thin Films β-Al-Mg Obtained Using PLD Technique

In this work, the pulsed laser deposition (PLD) technique was used to grow AlMg thin films from a $β-Mg_{2}Al_{3}$ target with nominal composition: 39.09 at.% Mg and 60.91 at.% Al. The paper presents the study of $β-Mg_{2}Al_{3}$ thin films deposited using the pulsed laser deposition technique. AlMg thin films were prepared on Si (400) substrates and deposited by means of using a QS-Nd:YAG laser (λ = 266, 355 nm). Samples were prepared with laser fluence (1.1 J/$cm^{2}$ and 1.6 J/$cm^{2}$) and at two different substrate (Si) temperatures (25°C and 200°C). The target possessed columnar structure and changes in chemical composition took place as a result of the influence of the laser irradiation. Investigations focused on structure and chemical composition showed that the films generally had nanocrystalline structure and that the quantity of Al and Mg varied in the films

Nanostructured Thin Films β-Al-Mg Obtained Using PLD Technique

In this work, the pulsed laser deposition (PLD) technique was used to grow AlMg thin films from a $β-Mg_{2}Al_{3}$ target with nominal composition: 39.09 at.% Mg and 60.91 at.% Al. The paper presents the study of $β-Mg_{2}Al_{3}$ thin films deposited using the pulsed laser deposition technique. AlMg thin films were prepared on Si (400) substrates and deposited by means of using a QS-Nd:YAG laser (λ = 266, 355 nm). Samples were prepared with laser fluence (1.1 J/$cm^{2}$ and 1.6 J/$cm^{2}$) and at two different substrate (Si) temperatures (25°C and 200°C). The target possessed columnar structure and changes in chemical composition took place as a result of the influence of the laser irradiation. Investigations focused on structure and chemical composition showed that the films generally had nanocrystalline structure and that the quantity of Al and Mg varied in the films

Morphology and Structure of the Erbium Stabilized Bismuth Oxide Thin Films Deposited by PLD Technique

The aim of the work was to obtain thin bismuth oxide films containing, at room temperature, the Bi1,5Er0,5O3 phase. This phase corresponds to the structure of the high-temperature δ-Bi2O3 phase, in pure bismuth oxide, characterized by the highest ionic conductivity of all known solid state ionic conductors. The high-temperature δ-Bi2O3 phase with the face centered cubic structure, in pure bismuth oxide, occurs only at temperature above 730°C. Stabilization of the δ-Bi2O3 phase at room temperature was achieved by an addition of the erbium together with the employ-ment of the Pulsed Laser Deposition (PLD) technique. The influence of an amount of Er alloying and the film thickness on surface morphology, microstructure, phase composition of thin films were investigated. The velocity of deposition of thin layers of bismuth stabilized with erbium in the PLD process using the Nd: YAG laser was about 0.5 nm/s.The investigation results of erbium doped bismuth oxide thin films deposited onto (0001) oriented Al2O3 monocrystalline substrate are presented. Thin films of uniform thickness, without cracks, and porosity were obtained. All deposited thin films (regardless of the film thickness or erbia (Er2O3) content) exhibited a columnar structure. In films stabilized with erbium, up to approx. 250 nm thickness, the columns have a diameter at the base from 25 to 75 nm. The columns densely and tightly fill the entire volume of the films. With increasing of the film thickness increases, porosity also significantly increases. In thin layers containing from 20 to 30 mole % Er2O3 the main identified phase at room temperature is Bi1,5Er0,5O3. It is similar to the defective fluorite-type structure, and belongs to the Fm-3m space group. This phase corresponds to the structure of the high-temperature δ-Bi2O3 phase in pure bismuth oxide

Osadzanie tlenkowych oraz międzymetalicznych cienkich filmów z wykorzystaniem lasera impulsowego (PLD) i wiązki elektronowej (PED)

In this work the pulsed laser deposition (PLD) and the pulsed electron beam deposition (PED) techniques were used for fabrication of Mo-Bi2O3, La1-xSrxCoO3, La1-xCaxCoO3 and Al-Mg thin films. An influence of ablation process basic parameters on the coatings structure and properties was discussed. Two types of laser ablation systems were applied: one equipped with a KrF excimer and second with a Q-switched Nd:YAG. Films were deposited on Si and MgO substrates. Scanning (SEM) and transmission (TEM) electron microscopy, atomic force microscopy (AFM) as well as X-ray diffraction (XRD) were used for structural analysis. Investigations focused on structure and chemical composition showed that smooth and dense thin films with nanocrystalline structure, preserving the composition of the bulk target, could be obtained by the both PLD and PED techniques. Research study showed that by a proper selection of PLD and PED process parameters it was possible to deposit films with significantly decreased amount and size of undesirably nanoparticulates.Osadzanie laserem impulsowym (PLD) oraz osadzanie impulsową wiązka elektronową (PED) wykorzystane zostało do wytwarzania cienkich filmów typu: Mo-Bi2O3, La1-xSrxCoO3, La1-xCaxCoO3 and Al-Mg oraz Al-Mg. Dyskutowano wpływ podstawowych parametrów procesu ablacji na strukturę i właściwości uzyskiwanych powłok. Wykorzystane zostały dwa typy systemów do ablacji; jeden z ekscymerowym laserem KrF i drugi na bazie lasera Nd:YAG z modulatorem dobroci (Q-Switch). Filmy osadzano na podłożu Si i MgO. Skaningowa (SEM) i transmisyjna (TEM) mikroskopia elektronowa, mikroskopia sił atomowych (AFM), oraz dyfrakcja rentgenowska (XRD) wykorzystana została do analizy strukturalnej. Badania skoncentrowane na strukturze i składzie chemicznym wykazały jednorodną i zwartą budowę cienkich nanokrystalicznych filmów uzyskanych metodami PLD i PED utrzymujących skład odparowywanych tarcz. Wykazano doświadczalnie, że odpowiednie dobranie parametrów procesu pozwala otrzymywać filmy o istotnym zminimalizowaniu ilości i wymiarów niekorzystnych nanocząstek w powłoce

Wear resistant coatings deposited by cold gas spraying

Naukowym i technologicznym celem badań było wytworzenie nanostrukturalnych powłok FeCuAl-Al2O3, WC-CoAl, Ni-Sn, TiC/Ti o grubości od 45 do 500 μm. Nanoproszki charakteryzujące się strukturą krystaliczną i równomiernym rozmieszczeniem składników otrzymywano, stosując wysokoenergetyczną syntezę mechaniczną. Proszek o strukturze nanokrystalicznej był nanoszony na podłoże bez istotnych zmian jego struktury i właściwości, z wykorzystaniem nowej technologii (natryskiwania zimnym gazem – CGS), pozwalającej uzyskiwać powłoki o dużej gęstości. Mikrostrukturę oraz skład chemiczny nanoproszków i nanoszonych powłok analizowano, wykorzystując mikroskopię świetlną, TEM, STEM, SEM/EDS, XPS oraz XRD. Ponadto mierzono współczynnik tarcia oraz odporność na ścieranie powłok. Przeprowadzone badania wykazały, że mikrostruktura powłok odpowiada strukturze nanoszonych proszków. Dzięki nanostrukturalnej budowie powłok, właściwej proporcji faz twardych i miękkich, natryskiwane zimnym gazem powłoki wykazują lepsze właściwości trybologiczne w porównaniu z materiałami standardowo stosowanymi w przemyśle i bioinżynierii.The basic scientific and technological aim of the research was the generation of nano-structured FeCuAl-Al2O3, WC-CoAl, Ni-Sn, TiC/Ti coatings having thicknesses of about 100-500 μm. High energy ball milling synthesis allowed the production of powders characterized by fine and homogeneous chemical distribution of elements, and an "ultrafine" (nanometer scale) crystalline structure. A new powerful deposition technology (Cold Gas Spray – CGS) was used to transfer the nanophased powder onto the substrate in the form of a dense coating with very little or no change of crystal structure and properties. The microstructure and composition of all prepared nano-powders and deposited coatings were investigated using light microscopy, TEM, STEM, SEM/EDS, XPS and XRD techniques. Hardness, and measurement of the coefficient of friction and wear resistance were carried out on the deposited coatings. It was found that the microstructure of the powder is maintained in the deposited coating. The nano phased structure, with an appropriate balance of hard and soft phases, allows the CGS coatings to exhibit better tribological properties than that of the examined benchmark materials