ABSTRACT CeO(2) thin films doped with neodymium oxides for application to gas sensors have been elaborated by the pulsed laser deposition technique. The films were deposited on orientated Si (100) substrates with variable deposition times... more
ABSTRACT CeO(2) thin films doped with neodymium oxides for application to gas sensors have been elaborated by the pulsed laser deposition technique. The films were deposited on orientated Si (100) substrates with variable deposition times (t = 90, 180 and 360 s) and molar fractions of Nd(2)O(3) (0, 6.5, 15, 21.5 and 27 at.%). The resulting Nd-CeO(2) thin films were characterized by means of X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy equipped with EDS (Energy Dispersive Spectrometer) microanalysis. From X-ray diffraction analyses, it is clearly established that the texture is modified by Nd additions. The preferred (111) orientations of the CeO(2) crystals change into the (200) orientation. The morphology of the CeO(2) grains changes from triangles, for pure CeO(2) thin films, to spherical grains for Nd-doped films. In addition, cell parameter analyses from X-ray diffraction data show that a partial chemical substitution of Ce by Nd should occur in the face-centred cubic lattice of ceria: this should give rise to Ce(1-x)Nd(x)O(2-z) phases with oxygen non-stoichiometry.
Research Interests: Materials Engineering, Condensed Matter Physics, Materials Science, Microscopy, Transmission Electron Microscopy, and 10 moreMedicine, Doping, Pulsed Laser Deposition, Thin Film, Microanalysis, Diffraction, Scanning Electron Microscope, Stoichiometry, Thin film deposition, and Biochemistry and cell biology
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Abstract Biomasses are a promising way to reduce the CO2 emissions in many industrial processes for the generation of energy and chemical base materials. To enable them to be used in related thermochemical conversion processes, their... more
Abstract Biomasses are a promising way to reduce the CO2 emissions in many industrial processes for the generation of energy and chemical base materials. To enable them to be used in related thermochemical conversion processes, their thermal behaviour and ash properties, which are the main limiting factors, must be investigated. In the present study, four feedstocks from two types of biomass are studied. The thermal behaviour is determined by thermal gravimetry (TG), differential thermal gravimetry (DTG), and differential scanning calorimetry (DSC) analysis. Comparable behaviour with only minor deviations is achieved for all biomass samples, which is largely independent of the exact properties of the feedstocks. The key goal of this work was to compare the properties of ashes obtained under 550 °C (standard procedure) and 200 °C (using plasma). Chemical analysis (applying X-ray fluorescence method) indicates the differences in the ash composition even in the particular types of biomass. Scanning electron microscopy (SEM-EDX) reveals that the composition is heterogeneously distributed over the different ash particles. Based on the different ashing temperatures, the transformation of the mineral phases in real conversion processes determined by X-ray diffraction (XRD) is simulated. Despite the heterogeneities in the ash particles’ chemical composition and distribution within each particular type of biomass, they demonstrate highly similar ash fusion temperatures. The thermochemical calculations using the FactSage™ software package have well reflected the ash fusion temperatures and the ash fusion interval.
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Research Interests: Engineering, Chemical Engineering, Materials Science, Biomedical Engineering, Metallurgy, and 15 moreCyclic Voltammetry, Medicine, Additive Manufacturing, Polyaniline, Adhesive, Polymer, Porosity, Coating, Ceramic, CHEMICAL SCIENCES, Conductive Polymer, Materials Testing, Cell Survival, aniline Compounds, and Power Sources
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TiB2-based coatings have been intensively developed due to their physical and mechanical properties, including excellent thermal stability and high hardness with good abrasion and corrosion resistance, which appear to be the most... more
TiB2-based coatings have been intensively developed due to their physical and mechanical properties, including excellent thermal stability and high hardness with good abrasion and corrosion resistance, which appear to be the most beneficial in industrial application. Previous investigations have shown that doping TiB2 with W, Ni and C can significantly reduce residual stresses and improve adhesion, making these coatings ideal on tools to machining aluminum alloys. The aim of this study was to analyze the effect of an Cr interlayer on the durability (adhesion) of the fabricated Ti1−xCrxB2 (x = 0; 0.03; 0.06; 0.10) films and determine the influence of Cr on their microstructure and mechanical properties. The structural characterization of Ti1−xCrxB2 coatings was carried out using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and atomic force microscopy. To investigate the mechanical properties, nano-scratch and—hardness tests (NST, NHT) were per...
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The study compared the properties of oxide coatings formed on aluminium alloys produced by: MAO (micro – arc oxidation), and the chemical method (oxidation in acid). Morphology, microstructure and of the coatings was analysed with a... more
The study compared the properties of oxide coatings formed on aluminium alloys produced by: MAO (micro – arc oxidation), and the chemical method (oxidation in acid). Morphology, microstructure and of the coatings was analysed with a scanning electron microscope SEM. Corrosion resistance were tested in potentiometer – dynamic. The layers produced by MAO significantly improved corrosion resistance. Coatings produced after 3 minutes of oxidation had better corrosion resistance than the coatings after 5 minutes of oxidation. The layers produced by chemical method didn’t improve corrosion resistance of aluminium alloy.