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General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Adhérence, Adhesion, Ecoulement laminaire, Laminar flow, Coating evaluation, Hierarchical structure, Insect residue adhesion, and Superhydrophobic

Surface contamination caused by insects on laminar flow wing surfaces causes a disruption of the flow, resulting in an increase in drag and fuel consumption. Consequently, the use of superhydrophobic coatings to mitigate insect residue adhesion was investigated. A range of hierarchical superhydrophobic coatings with different surface chemistry and topography was examined. Candidate coatings were characterized in terms of their morphology and hydrophobic properties by scanning electron microscopy (SEM) and static and dynamic contact angle measurements, respectively. Arithmetic mean surface roughness (Ra) values were measured using profilometry. Only superhydrophobic coatings with a specific topography showed complete mitigation against insect residue adhesion. A surface which exhibited a specific microstructure (Ra = 5.26 μm) combined with a low sliding angle (SA = 7.6°) showed the best anti-contamination properties. The dynamics of an insect impact event and its influence on the wetting and adhesion mechanisms of insect residue to a surface were discussed.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Acier inoxydable austénitique, Austenitic stainless steel, Pression partielle, Partial pressure, Spectre photoélectron RX, X-ray photoelectron spectra, Electrochemical impedance spectroscopy (EIS), H2S-Cl-, Mott-Schottky, Passive film, and X-ray photoelectron spectroscopy (XPS)

In oil-gas production environments, presence of H2S-Cl- can induce deterioration of the passive film, leading to pitting corrosion of stainless steels. In this paper, by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and capacitance measurements (Mott-Schottky analysis), the electrochemical behaviour of AISI 316L austenitic stainless steel was investigated in Cl- solutions under different H2S partial pressures (from 0 to 1.0 bar). The results indicated that presence of H2S in Cl- solution can accelerate both the cathodic and anodic current density, leading to a metastable passive state in higher passive potential range, changing the semiconductor behaviour from p-type to n-type, increasing its susceptibility to corrosion. XPS analysis was employed to characterize the surface film after potentiostatic polarization, whose results provide good evidences for the electrochemical measurements.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Composé de métal de transition, Transition element compounds, Composé minéral, Inorganic compounds, Couche mince, Thin films, Croissance film, Film growth, Dépôt chimique phase vapeur, CVD, Liaison chimique, Chemical bonds, Matériau dopé, Doped materials, Oxyde de zinc, Zinc oxide, Zinc óxido, O Zn, ZnO, Chemical bonding configuration, Electrical properties, and Ga doped ZnO

The electrical and chemical properties of low pressure chemical vapor deposition (LP-CVD) Ga doped ZnO (ZnO:Ga) films were systematically investigated using Hall measurement and X-ray photoemission spectroscopy (XPS). Diethylzinc (DEZ) and O2 gas were used as precursor and reactant gas, respectively, and trimethyl gallium (TMGa) was used as a Ga doping source. Initially, the electrical properties of undoped LP-CVD ZnO films depending on the partial pressure of DEZ and O2 ratio were investigated using X-ray diffraction (XRD) by changing partial pressure of DEZ from 40 to 140mTorr and that of O2 from 40 to 80mTorr. The resistivity was reduced by Ga doping from 7.24 x 10-3 Ωcm for undoped ZnO to 2.05 x 10-3 Ωcm for Ga doped ZnO at the TMG pressure of 8mTorr. The change of electric properties of Ga doped ZnO with varying the amount of Ga dopants was systematically discussed based on the structural crystallinity and chemical bonding configuration, analyzed by XRD and XPS, respectively.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Bicouche, Bilayers, Composé minéral, Inorganic compounds, Couche mince, Thin films, Evaporation faisceau électronique, Electron beam evaporation, Microscopie électronique balayage, Scanning electron microscopy, Oxyde d'aluminium, Aluminium oxide, Aluminio óxido, Oxyde de magnésium, Magnesium oxide, Magnesio óxido, Al O, Al2O3, Mg O, MgO, Magnesium oxide/alumina, Oblique angle deposition, SEM, and X-ray

The electrical and morphological properties of magnesium oxide (MgO)/alumina (Al2O3) bilayered thin films prepared by electron beam evaporation at oblique incidence are reported. The MgO thin films are deposited when the incline angle is 55° on various Al2O3 thin films incline angles. A columnar grain with a roofing-tile-shaped surface is observed in these MgO/Al2O3 thin films. X-ray pole figures and θ-2θ scan, ω-scan are used to characterize in-plane and out-of-plane textures. The relationships between ω-FWHM, capacitor, leakage current, and the inclined angles are studied. The morphology is investigated by using scanning electron microscope (SEM). So the oblique angle deposition method is an effective way to control the microstructure of thin films.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Composition chimique, Chemical composition, Nanotube, Nanotubes, Sodium, Titanate, Titanates, Na, Functionalization, Silane coupling agents, Sodium content, Solvents, and Titanate nanotubes

One of the major challenges in the development of nanocomposites based on a polymer matrix and highly polar ceramic nanofillers is the lack of the compatibility between these two components. In order to improve the chemical interaction between titanate nanotubes (TTNT) and polymer matrix, such as nylon 11,3-aminopropyltriethoxysilane (APTES) was grafted onto TTNT. The effects of the TTNT chemical composition i.e. sodium content and solvent type on the grafting silane efficiency were thoroughly studied through CHN elemental analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), surface area and zeta potential measurements. The present study brings evidences supporting aqueous ethanol as more efficient reaction medium for TTNT functionalization with APTES, independent of the sodium content of nanotubes, when compared with pure water. It is also worth noting that within aqueous ethanol medium, TTNT with low sodium content are more efficiently grafted than TTNT with high sodium content. Successful APTES grafting decreases concentration of the hydroxyl groups on TTNT surfaces and enables its future application for the fabrication of nylon 11 nanocomposites.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Composé minéral, Inorganic compounds, Croissance film, Film growth, Méthode MOCVD, MOCVD, Nitruration, Nitridation, Nitrure de gallium, Gallium nitride, Galio nitruro, Semiconducteur, Semiconductor materials, Ga N, GaN, Nonpolar, and Raman spectra

The effects of substrate nitridation on the growth of nonpolar a-plane GaN directly deposited on r-plane sapphire by metalorganic chemical vapor deposition (MOCVD) were investigated. Using nitridation, high-quality a-plane GaN with flat surface was acquired. On the contrary, if the nitridation layer was removed, the epitaxial a-plane GaN exhibited deep triangular pits and poor crystalline properties. This could be attributed to the fact that uniform-distributed AlN grains were introduced by nitridation, which might act as the nucleation layer for the following a-plane GaN growth. The effects of substrate nitridation on the evolutions of anisotropic morphologies and crystalline properties were also studied by artificially interrupting the growth at different stages. The consequences suggested the nitridation layer could contribute to surface coalescence of a-plane GaN. The reasons responsible for this phenomenon were probed by Raman spectrum, and a model was proposed to explicate the effects of nitridation on the growth of a-plane GaN.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Conductivité ionique, Ionic conductivity, Couche mince, Thin films, Cristallinité, Crystallinity, Cristalinidad, Structure surface, Surface structure, Zircone stabilisée, Stabilized zirconia, Zircona estabilizada, Substrate surface, and YSZ

Thin film properties can be controlled to a large degree by the substrate upon which the film is grown. The substrate surface can affect the film's crystal phase and microstructure and, thereby, many other properties. In this study, yttria-stabilized zirconia films on single crystal MgO and Al2O3 substrates with polished, ion cleaned, or milled surfaces were studied. The different substrate surfaces influenced the thin films' microstructures and ionic conductivities. The increased roughness of the milled surfaces led to significant decreases in both the crystallinity and the ionic conductivity of the films. Ion cleaning of the substrate surface immediately before deposition did not affect the conductivity of films on MgO substrates but led to conductivity reductions by a factor of about 4 on sapphire substrates.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Cryogénie, Cryogenics, Fer, Iron, Grosseur grain, Grain size, Laminage à froid, Cold rolling, Microstructure, Métal transition, Transition elements, Résistance corrosion, Corrosion resistance, Fe, and Cryogenic cold rolling

The effects of cold rolling temperature on grain size and grain orientation of pure iron were investigated. Comparing with sample rolled at room temperature, the grain refinement was facilitated in sample obtained by cryogenic cold rolling at liquid-nitrogen temperature. However, the grain orientation changed little for two samples. It was shown that cathodic hydrogen evolution reaction could govern the corrosion reaction for pure iron in sulfuric acid solution. The grain refinement obtained by rolling improved the corrosion resistance of iron in sulfuric acid solution, borate buffer solution and borate buffer solution with chloride ion. However, comparing with iron rolled at room temperature, the corrosion resistance of iron obtained by cryogenic temperature rolling was lower. Comparing with iron rolled at room temperature, higher dislocation density in iron rolled at cryogenic temperature reduced its corrosion resistance.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Acier non allié, Carbon steels, Adhérence, Adhesion, Dépôt conversion, Conversion coating, Depósito conversión, Fer, Iron, Microscopie force atomique, Atomic force microscopy, Microscopie électronique balayage, Scanning electron microscopy, Métal transition, Transition elements, Traitement surface, Surface treatments, Zirconium, Fe, Zr, AFM, Cathodic disbonding, EIS, FE-SEM, and Zirconium conversion coating

The effect of zirconium-based surface treatment on the cathodic disbonding resistance and adhesion performance of an epoxy coated mild steel substrate was investigated. The obtained data from pull-off, cathodic disbonding test and electrochemical impedance spectroscopy (EIS) indicated that the zirconium conversion layer significantly improved the adhesion strength and cathodic disbonding resistance of the epoxy coating. This may be attributed to formation of some polar zirconium compounds on the surface and increment of surface roughness, that were evident in the results of field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), respectively.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Couche mince, Thin films, Diffraction RX, XRD, Microscopie tunnel balayage, Scanning tunneling microscopy, Métal transition, Transition elements, Or, Gold, Silicium, Silicon, Au, Si, STM, and Thin film

We report here the effects of substrate temperature on the orientation and surface morphology of 100 nm thick gold films, using scanning tunneling microscopy and X-ray diffraction. The gold films were deposited using molecular beam epitaxy technique onto Si(111) 7 × 7 substrates. Ex situ characterizations are performed using scanning tunneling microscope at room temperature. X-ray diffraction measurements reveal the (111) orientation of the film deposited at 580°C. We present data showing the evolution of the RMS roughness amplitude of the gold films as a function of substrate temperature during deposition. For our purposes, the best compromise between roughness and grain size is found to occur for a substrate temperature maintained at 580°C.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Europium, Lanthanide, Rare earths, Luminescence, Nanoparticule, Nanoparticles, Traitement surface, Surface treatments, Eu, Dibenzoylmethane, Europium fluoride, Phenanthroline, and Surface modification

Reaction between Eu(NO3)3 and NH4F in aqueous media was applied to produce EuF3 doughnut-like aggregates with a diameter of 200-500 nm and thickness of 50-150 nm composed of nanoparticles with a mean diameter of 16 nm. The impregnation, sorption and mechanochemical treatment were used for surface modification of EuF3 doughnut-like particles with 1,10-phenanthroline and sodium dibenzoylmethanate which are sensitizing ligands for Eu3+ luminescence. The data of transmission electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and luminescence spectroscopy have proved that the organic ligands are coordinated to surface Eu3+ ions, forming surface complexes. The surface modification of the EuF3 nanoparticles with sodium dibenzoylmethanate and 1,10-phenanthroline leads to increase in the luminescence intensity at 612 nm (5D0 → 7F2 transition) in comparison with the luminescence intensity of the unmodified EuF3 nanoparticles. Energy transfer from the ligand to Eu3+ ion in the surface complexes makes a main contribution to this effect.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Dépôt centrifugation, Spin-on coating, Multicouche, Multilayers, Résistivité couche, Sheet resistivity, Spectre absorption, Absorption spectra, Counter electrode, Multilayer graphene, Optical transmission, Sheet resistance, and Spin coating

This paper reports the modification of electrical and optical properties of graphene film by spin coating polyethylene glycol (PEG) solution onto the graphene oxide film followed by thermal reduction process. The PEG solution was deposited onto the graphene oxide film at different spin coating speeds (1000, 1500, 2000, 2500 and 3000 rpm). The introduction of PEG at appropriate spin coating speed results in lower sheet resistance and optical transmittance, probably due to better alignment and stacking of the graphene sheets. It is interesting to find that the dye sensitized solar cell with PEG-modified graphene film as counter electrode showed 4 times increase in power conversion efficiency as compared to that with unmodified graphene film.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Composé de métal de transition, Transition element compounds, Composé minéral, Inorganic compounds, Oxydation, Oxidation, Oxyde de titane, Titanium oxide, Titanio óxido, Prétraitement, Pretreatment, Pretratamiento, O Ti, TiO2, CO oxidation, Pretreatment conditions, and Titanium dioxide

The effect of pretreatment conditions in reductive and oxidative atmosphere on physicochemical properties and catalytic activity of TiO2 was studied. TiO2 was characterized using: XRD, SEM, TPR-H2, O2 and CO chemisorption methods, and tested in the reaction of CO oxidation in air. Experimental results indicated that the kind of pretreatment conditions has a significant influence on structural properties and activity of the studied oxide. It was claimed that pretreatment in hydrogen favors anatase → rutile transformation. Moreover, rutile was more easily reducible than the anatase phase despite its high thermodynamic stability. Catalytic tests showed that pretreatment in hydrogen enhances conversion of CO more than annealing in oxygen atmosphere.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Bande interdite, Energy gap, Composé de métal de transition, Transition element compounds, Composé minéral, Inorganic compounds, Couche mince, Thin films, Croissance film, Film growth, Indium, Magnétron, Magnetrons, Pulvérisation cathodique, Cathode sputtering, Recuit, Annealing, Spectre photoélectron RX, X-ray photoelectron spectra, In, 61.72.Cc, 71.20.Nr, 78.20.Ci, 81.15.Cd, 82.80.Pv, Bandgap, ITO, PACS, Post-annealing, and XPS

We report effects of post-annealing on Indium Tin Oxide (ITO) thin films by their physical, electrical, optical, and electronic properties. Carrier concentrations increase up to annealing temperatures of 400 °C, and then decrease at higher annealing temperatures. Burstein-Moss effect occurs as a function of annealing temperature with the highest optical bandgap of 4.17 eV achieved at 400 °C. X-ray photoelectron spectroscopy revealed a ~0.3 eV shift in the Fermi level of the annealed ITO films at 400 °C, and the shift was reduced for temperatures higher than 400 °C. In addition, the results of curve-fitting for the core levels showed a change of ratios of SnO2 and oxygen in the oxygen deficient regions after annealing. This is correlated to the change of carrier concentration and optical bandgap in the ultraviolet and near-infrared regions at different annealing temperatures.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Azote, Nitrogen, Croissance film, Film growth, Hyperfréquence, Microwave radiation, Méthode PECVD, PECVD, Spectre IR, Infrared spectra, Spectre photoélectron RX, X-ray photoelectron spectra, Spectre transformée Fourier, Fourier transform spectra, N, 68.55.J, 68.60.Bs, 78.55.Qr, 81.05.U, DLC, ECR Microwave Plasma CVD, FTIR, PL61.05.Tv, and XPS

Diamond like carbon (DLC) and nitrogenated diamond like carbon (DLC:N) films have been deposited by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-MP CVD) on Si (110), steel and glass substrates, using CH4 and N2 as plasma source. The effect of nitrogen doping on the optical, electrical, structural and mechanical properties of films was investigated. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy results showed that sp2 bonded carbon phases increased while the sp3 bonded carbon phases decreased by nitrogen doping. Microhardness measurements showed a decrease in hardness (from 75 to 69 GPa) according to nitrogen incorporation. Average transmittance of all the films was over 90% and band gap energy (Eg) of the films decreased due to increasing nitrogen flow rate. The film morphology was studied using the atomic force microscopy (AFM). Electrical properties were characterized by Hall measurement. Undoped DLC was p-type with a conductivity of 9.81 × 10-6 (Ω cm)-1. DLC films became n-type by nitrogen doping. The best conductivity value for the nitrogen doped DLC films was found 2.77 × 10-5 (Ω cm)-1. PL spectra of DLC and DLC:N films showed three peaks at 405 nm (3.06 eV), 533 nm (2.32 eV) and 671 nm (1.84 eV).

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Corrosion, Effet physique rayonnement, Physical radiation effects, Faisceau pulsé, Pulsed beam, Haz pulsado, Faisceau électron, Electron beams, Fusion, Melting, Microscopie électronique transmission, Transmission electron microscopy, Microstructure, Transformation phase, Phase transformations, Large area electron beam melting, Martensite, Pulsed electron beam irradiation, TEM, and Ti-6Al-4V

The use of titanium alloys in biomedical applications continues to increase due to the excellent stiffness to weight ratio and high corrosion resistance. In order to improve the surface wettability and corrosion properties of a Ti-6Al-4V alloy, the surface treatment method, large area electron beam melting technique was investigated. Polished samples were subject to pulsed treatments of 1,15 and 25 at 1.38J/cm2 beam energy. Surface roughness and contact wetting angles were reduced as a result of the treatment. Microstructural analysis of the surface by XRD and FIB-TEM revealed a martensitic alpha prime phase formed as a result of the high cooling rates induced by the treatment. The presence of this homogenous martensite layer was shown to facilitate a compact passive oxide layer formation during corrosion, thus improving corrosion rates by several orders of magnitude compared to an untreated sample. Large area electron beam melting of Ti-6Al-4V induced a number of changes to the near surface microstructure of the samples, all of which could be used to tailor mechanical and corrosion properties to that of a desired application, without compromising the bulk material properties. These are explored in detail in this work.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Acier antifriction, Bearing steel, Acero antifricción, Durée vie fatigue, Fatigue life, Longevidad fatiga, Fatigue, Frottement, Friction, Implantation ion, Ion implantation, Laminage à chaud, Hot rolling, Tribologie, Tribology, Usure, Wear, Friction and wear, and Hot rolling contact fatigue life

The Cr4Mo4Ni4V bearing material was implanted by N + Zr dual element implantation process. The mechanical properties were investigated by nanohardness tests, friction and wear tests, as well as hot rolling contact fatigue life tests. The surface structures of the planted samples were studied by GXRD, AES, XPS and TEM tests. The results showed that the N + Zr implanted sample exhibits higher surface hardness, anti-friction and wear-resistance properties and resistance to hot contact fatigue. After implantation, amorphous phase, microcrystalline phase and new alloy phases are formed in implanted region. The new phases and structures take the important roles in improving the surface mechanical properties of the bearing material.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Croissance film, Film growth, Magnétron, Magnetrons, Métal transition, Transition elements, Pulvérisation cathodique, Cathode sputtering, Pulvérisation réactive, Reactive sputtering, Résistance oxydation, Oxidation resistance, Resistencia a la oxidación, Silicium, Silicon, Vanadium, Si, V, Mechanical properties, Structure, TiSi(V)N films, and Vanadium oxide

In the last years, vanadium rich films have been introduced as possible candidates for self-lubrication at high temperatures, based on the formation of V2O5 oxide. The aim of this investigation was to study the effect of V additions on the structure, mechanical properties and oxidation resistance of Ti-Si-V-N coatings deposited by DC reactive magnetron sputtering. The results achieved for TiSiVN films were compared and discussed in relation to TiN and TiSiN films prepared as reference. All coatings presented a fcc NaCl-type structure. A shift of the diffraction peaks to higher angles with increasing Si and V contents suggested the formation of a substitutional solid solution in TiN phase. Hardness and Young's modulus of the coatings were similar regardless on V content. The onset of oxidation of the films decreased significantly to 500 °C when V was added into the films; this behaviour was independent of the Si and V contents. The thermogravimetric isothermal curves of TiSiVN coatings oxidized at temperatures below the melting point of α-V2O5 (~685 °C) showed two stages: at an early stage, the weight increase over time is linear, whilst, in the second stage, a parabolic evolution can be fitted to the experimental data. At higher temperatures only a parabolic evolution was fitted. α-V2O5 was the main phase detected at the oxidized surface of the coatings. Reduction of α-V2O5 to β-V2O5 phase occurred for temperatures above its melting point.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Aniline polymère, Polyanilines, Méthode dynamique moléculaire, Molecular dynamics method, Rugosité, Roughness, Simulation, Structure surface, Surface structure, Traitement thermique, Heat treatments, Heat treatment, Molecular dynamics simulation, Nanostructured film, Polyaniline, and Roughness parameters

The influence of drying temperature, T on the surface structure of polyaniline (PANI) nanostructured films dried at temperatures less than the glass transition temperature, Tg and between Tg and melting temperature, Tm was investigated by atomic force microscopy (AFM) and ZeScope optical profilometry. The expected power law behavior associated with surface roughness over small length scales was confirmed at different drying temperatures. To correlate the value of the film thickness determined based on AFM with that obtained from ZeScope measurements, a model of height correcting factor is introduced. The variation in saturated roughness of the PANI film was determined to follow a power law model in the range of T < Tg, with a saturated roughness exponent of 4.48 ± 0.4. The structure of the PANI film has been investigated based on molecular dynamics simulation. The applicability of power law model was confirmed by simulations, based on which the saturated roughness exponent was determined to be 4.90 ±0.5.