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Search results for: graphene oxide coatings
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Post-plasma oxidation in water of graphene paper surface
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Tin Oxide Encapsulated into Pyrolyzed Chitosan as a Negative Electrode for Lithium Ion Batteries
PublicationTin oxide is one of the most promising electrode materials as a negative electrode for lithium-ion batteries due to its higher theoretical specific capacity than graphite. However, it suffers lack of stability due to volume changes and low electrical conductivity while cycling. To overcome these issues, a new composite consisting of SnO2 and carbonaceous matrix was fabricated. Naturally abundant and renewable chitosan was chosen...
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Functional fluorine-doped tin oxide coating for opto-electrochemical label-free biosensors
PublicationSensors operating in multiple domains, such as optical and electrochemical, offer properties making biosensing more effective than those working in a single domain. To combine such domains in one sensing device, materials offering a certain set of properties are required. Fluorine-doped tin oxide (FTO) thin film is discussed in this work as functional optically for guiding lossy modes and simultaneously electrochemically, i.e....
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High performance LaNi1-xCoxO3-δ (x = 0.4 to 0.7) infiltrated oxygen electrodes for reversible solid oxide cells
PublicationOxygen electrodes prepared by infiltration of yttria stabilized zirconia backbone with Ce0.8Gd0.2O1.95 barrier layer and LaNi1-xCoxO3-δ (x=0.4 to 0.7) catalyst for application in reversible solid oxide cells have been studied. The effect of temperature and Ni:Co ratio on their phase composition, microstructure and electrochemical properties are discussed. It was shown that oxygen electrodes infiltrated with LaNi0.5Co0.5O3-δ had...
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Development of SPME fiber coatings with tunable porosity for physical confinement of ionic liquids as an extraction media
PublicationExtending the use of ionic liquids in sample preparation techniques remains a challenge. This paper presents procedures enabling the easy application of ionic liquids to the SPME technique. For this purpose, two approaches for producing a porous silica coating on a metal rod were investigated. Two silica precursor and porogen systems were used in the research: K2SiO3 + Formamide and Tetramethyl-orthosilicate + Polyethylene oxide....
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Zinc Oxide and Zinc Oxide Nanoparticles Impact on In Vitro Germination and Seedling Growth in Allium cepa L.
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Acetate-Induced Disassembly of Spherical Iron Oxide Nanoparticle Clusters into Monodispersed Core−Shell Structures upon Nanoemulsion Fusion
PublicationIt has been long known that the physical encapsulation of oleic acid-capped iron oxide nanoparticles (OA−IONPs) with the etyltrimethylammonium (CTA+) surfactant induces the formation of spherical iron oxide nanoparticle clusters (IONPCs). However, the behavior and functional properties of IONPCs in chemical reactions have been largely neglected and are still not well-understood. Herein, we report an unconventional ligand-exchange...
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Tin oxide nanoparticles from laser ablation encapsulated in a carbonaceous matrix – a negative electrode in lithium-ion battery applications
PublicationThis report concerns carbonaceous electrodes doped with tin(II) oxide nanoparticles. Tin nanoparticles are obtained by pulsed laser ablation in water. Crystalline nanoparticles have been encapsulated in a carbonaceous matrix formed after pyrolysis of a mixture consisting of tin/tin(IV) oxide nanoparticles and gelatine. The obtained material is characterized by means of X-ray diffraction, selected area diffraction, scanning electron...
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Intense and stable room-temperature photoluminescence from nanoporous vanadium oxide formed by in-ambient degradation of VI3 crystals
PublicationVanadium oxides have attracted research interest because their optoelectronic properties make them optically active with room-temperature photoluminescence (PL) emission, which, however, is not sufficiently intense for real applications. For this reason, many nanostructured vanadium oxides are currently fabricated through several precursors and different treatments to improve the PL efficiency and enhance the PL intensity. Herein,...
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Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering.
PublicationIron oxide films were deposited using high power impulse magnetron sputtering (HiPIMS) of an iron cathode in an argon/oxygen gas mixture at different gas pressures (0.5~Pa, 1.5~Pa, and 5.0~Pa). The HiPIMS system was operated at a repetition frequency $f = 100$~Hz with a duty cycle of 1~\%. A main goal is a comparison of film growth during conventional and electron cyclotron wave resonance-assisted HiPIMS. The deposition plasma...
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Impedance spectroscopy of undoped cerium oxide.
PublicationW pracy przedstawiono badania impedancyjne niedomieszkowanego tlenku ceru. Wyniki wskazują na występowanie zjawiska dyfuzji,???? które nie są (.. jest.?)związane z odpowiedzią elektrodową. Rozważania teoretyczne dopuszczają obserwowanie impedancji Warburga, która reprezentuje zjawisko dyfuzji w przewodnikach mieszanych, jednakże niewiele informacji na ten temat można znaleźć w literaturze. W związku z tym szczegółowe badania zródła...
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Structural studies of titanium oxide multilayers
PublicationW pracy przedstawiono wyniki badań cienkich warstw TiO2 przy wykorzystaniu dyfrakcji rentgenowskiej i anihilacji pozytonów. Warstwy były wytwarzane różnymi metodami. Badania pozwalają na określenie optymalnych, z punktu widzenia późniejszych zastosowań, parametrów warstw.
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Electron collisions with ethylene oxide molecules
PublicationZmierzono całkowite przekroje czynne na rozproszenie elektronów na drobinach tlenku etylenu w zakresie energii od 0.7 do 400 eV. Obliczono przekroje czynne na zderzenia sprężyste oraz przekroje czynne na jonizację. Otrzymane wyniki obliczeń są zgodne z wynikami eksperymentalnymi w pokrywającym się przedziale energii zderzenia. Wyniki uzyskane dla tlenku etylenu porównano z przekrojami czynnymi dla jego izoelektronowego odpowiednika...
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On the superconducting state in Ba0.6K0.4BiO3 perovskite oxide
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Perovskites in Solid Oxide Fuel Cells
PublicationPrzeglądowa publikacja dotycząca wykorzystania ceramicznych materiałów perowskitowych w tlenkowych ogniwach paliwowych.
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Electronic and ionic relaxations in oxide glasses
PublicationDokonano przeglądu procesów relaksacyjnych w szkłach wykazujących elektronowy i elektronowo-jonowy charakter przewodnictwa elektrycznego. Na podstawie badań impedancyjnych przedstawiono klasyfikację szkieł o mieszanym elektronowo-jonowym przewodnictwie. Wskazano na zalety metody tarcia wewnętrznego do badań procesów relaksacyjnych w szkłach tlenkowych.
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Sustainable energy system combined biogas-feedSolid Oxide Fuel Cell and Microalgae technology
PublicationIn the new frontier of energy and environmental safety, new efficient and clean safe energy conversion systems are required. In this sense, the present work is framed within the context of Circular Economy and proposes a multidisciplinary study for the development of more efficient, economically viable and non-polluting energy conversion systems, based on the synergetic combination of different technologies: fuel cells, biofuels,...
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Electrochemical detection of 4,4',5,5'-tetranitro-1H,1'H-2,2'-biimidazole on boron-doped diamond/graphene nanowall electrodes
PublicationWe present a promising approach to the electroanalytical detection of a specific nitroaromatic explosive in landfill leachates (LLs) that originated from a municipal solid waste plant. The paper is focused but not limited to the sensing of 4,4',5,5'-tetranitro-1H,1'H-2,2'-biimidazole (TNBI) using differential pulse voltammetry and cyclic voltammetry. Highly electroactive nanocarbon was applied to determine low concentrations of...
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Differential Quadrature Method for Dynamic Buckling of Graphene Sheet Coupled by a Viscoelastic Medium Using Neperian Frequency Based on Nonlocal Elasticity Theory
PublicationIn the present study, the dynamic buckling of the graphene sheet coupled by a viscoelastic matrix was studied. In light of the simplicity of Eringen's non-local continuum theory to considering the nanoscale influences, this theory was employed. Equations of motion and boundary conditions were obtained using Mindlin plate theory by taking nonlinear strains of von Kármán and Hamilton's principle into account. On the other hand, a...
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Annealing of indium tin oxide (ITO) coated optical fibers for optical and electrochemical sensing purposes
PublicationGlass and fiber structures with Indium Tin Oxide (ITO) coating were subjected to annealing in order to identify impact of the thermal treatment on their optical and electrochemical properties. It is shown that the annealing process significantly modifies optical properties and thickness of the films, which are crucial for performance of optical fiber sensors. Moreover, it visibly improves electrochemical activity of ITO on glass...
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Investigation of catalytic layers on anode for solid oxide fuel cells operating with synthetic biogas
PublicationIn this paper solid oxide fuel cells operating with dry synthetic biogas have been examined. In order to increase their stability the layers of CuO-CeO2, Cu1.3Mn1.7O4 and Y0.08Sr0.92Ti0.8Fe0.2O3 -δ have been deposited on the Ni-YSZ anode site. These layers should catalyze the internal biogas reforming and prevent the carbon deposition on the anode site. It has been found that CuO-CeO2 and Cu1.3Mn1.7O4 catalysts led to an increase...
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Investigation of functional layers of solid oxide fuel cell anodes for synthetic biogas reforming
PublicationSolid oxide fuel cells (SOFCs) are one of the most promising energy conversion devices due to their high efficiency, low pollution and fuel flexibility. Unfortunately, when hydrocarbons are used as a fuel, for example in the form of a biogas, solid carbon can deposit on the anode surface. This process leads to the degradation of the fuel cell performance. A possible solution to this problem is to apply an additional catalytic material,...
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Defining efficient modes range for plasma spraying coatings
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Electrochemical approach to evaluate the interlayer adhesion of organic coatings
PublicationZastosowano elektrochemiczną spektroskopię impedancyjną do wyznaczania międzywarstwowej adhezji w powłokach organicznych. Zbadano różne zestawy powłok do ochrony samochodów. Zastosowano dwie elektrody wykonane z prądoprzewodzącego tuszu umieszczone pomiędzy warstwami powłokowymi. Stwierdzono, że utrata adhezji międzywarstwowej następuje podobnie jak zmiany energii aktywacji przewodnictwa jonowego w obszarze międzywarstwowym. Uzyskane...
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Effect of WC on electroposition and corossion behaviour of chromium coatings
PublicationWłaściwości warstw chromowych zawierających różne ilości drobin WC zbadano metodą XPS, EPS oraz XRD. Metody te pozwoliły określić morfologię i skład chemiczny powłok. Właściwości antykorozyjne określono dla różnych czasów ekspozycji próbek w elektrolicie zawierającym 0,01 mol L-1 za pomocą metody woltamperometrycznej oraz spektroskopii impedancyjnej. Badania wykazały, że obecność WC w warstwach chromowych otrzymanych z kąpieli...
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Measurement microsystem for high impedance spectroscopy of anticorrosion coatings
PublicationW artykule przedstawiono mikrosystem do pomiarów bardzo dużych impedancji ukierunkowany na identyfikację parametrów powłok antykorozyjnych metodą spektroskopii impedancyjnej. Do wyznaczania składowych ortogonalnych sygnałów pomiarowych zastosowano w nim technikę cyfrowego przetwarzania sygnałów. Pozwoliła ona na uzyskanie szerokiego zakresu częstotliwości pomiarowych, zwłaszcza bardzo niskich, od ćHz, przy zachowaniu prostej konstrukcji...
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Electrophoretic Deposition of Chitosan Coatings on the Porous Titanium Substrate
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Gold nanoparticles and their coatings, their effect on cells and their interaction with radiation
PublicationTwo nanometre gold nanoparticles (AuNPs), bearing sugar moieties and/or polyethylene glycolamine (PEG-amine), were synthesised and evaluated for their in vitro toxicity and ability to radiosensitise cells with 220 kV and 6 MV X-rays, using four cell lines representing normal and cancerous skin and breast tissues. In addition to the observed intrinsic cancer-selective chemotoxicity, these AuNPs acted as radiosensitisers in combination with...
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Adhesion of organic coatings to hot-dip galvanized steel
PublicationDuplex systems provide long-time corrosion protection, much longer than the sum of the lifetimes of zinc and paint used individually. However loss of adhesion between coating and zinc substrate is often found in practice. Different methods of zinc surface preparations are used in the fi eld. The aim of this study was to examine and compare coating protection when the old zinc surface, stored during long-time period (15 years) in...
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On the use of bilinear transformation for parameter identification of anticorrosion coatings
PublicationW artykule przedstawiono metodę identyfikacji parametrów powłok antykorozyjnych modelowanych wieloelementowymi układami zastępczymi. Metoda wykorzystuje właściwości przekształcenia biliniowego, które umożliwia przedstawienie funkcji układowej wieloparametrowego modelu jako funkcji każdego indywidualnego parametru. Odwrotne przekształcenie biliniowe pozwala na wyznaczenie wartości każdego z parametrów modelu z osobna na podstawie...
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Protective properties of the chromium - titanium carbonitryde composite coatings.
PublicationZbadano właściwości ochronne warstw chromowych zawierających dodatki węglika tytanu poprawiającego właściwości mechaniczne warstw. badania ditycżą roztworów kwasu siarkowego. Badania przeprpwadzono metodą spektroskopii impedamncyjnej. Wykazano ze właściwosci ochronne warswt są lepsze dzięki sdyspergowanym cząstkowm węglika tytanu.
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CGO as a barrier layer between LSCF electrodes and YSZ electrolyte fabricated by spray pyrolysis for solid oxide fuel cells
PublicationPerovskite La0.6Sr0.4Co0.2Fe0.8O3 − δ (LSCF) is often used as a cathode material for solid oxide fuel cells (SOFC) due to high mixed ionic and electronic conductivity and good catalytic activity. Unfortunately, sintering of the LSCF cathode together with the yttria stabilized zirconia (YSZ) electrolyte, leads to formation of the La2Zr2O7 and SrZrO3 phases in the interface. These phases increase the resistance of the cell. To avoid...
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The effect of boron concentration on the electrical, morphological and optical properties of boron-doped nanocrystalline diamond sheets: Tuning the diamond-on-graphene vertical junction
PublicationIn this paper, the effect of boron doping on the electrical, morphological and structural properties of free-standing nanocrystalline diamond sheets (thickness ~ 1 μm) was investigated. For this purpose, we used diamond films delaminated from a mirror-polished tantalum substrate following a microwave plasma-assisted chemical vapor deposition process, each grown with a different [B]/[C] ratio (up to 20,000 ppm) in the gas phase....
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The Effect of Sodium Tetrafluoroborate on the Properties of Conversion Coatings Formed on the AZ91D Magnesium Alloy by Plasma Electrolytic Oxidation
PublicationMagnesium and its alloys are widely used in many areas because of their light weight, excellent dimensional stability, and high strength-to-weight ratio. However, the material exhibits poor wear and corrosion resistance, which limits its use. Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on Mg and their alloys. The influence of the additions of sodium tetrafluoroborate...
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LaNi1-xCoxO3-δ(x=0.4 to 0.7) cathodes for solid oxide fuel cells by infiltration
PublicationPerformance of LaNi 1-x Co x O 3−δ (LNC) (x=0.4 to 0.7) as a cathode in solid oxide fuel cell (SOFC) is evaluated. Symmetrical cathode/electrolyte/cathode cells for electrochemical testing are prepared by infiltration of yttria stabilized zirconia (YSZ) backbone with LNC solutions. It is showed that the cathode infiltrated with LaNi 0.5 Co 0.5 O 3−δ (LNC155) has the lowest polarization resistance and activation energy, 197 mΩ cm...
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Upcycling Waste Polypropylene into Graphene Flakes on Organically Modified Montmorillonite
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Dispersion, compatibility, and rheological properties of graphene-modified asphalt binders
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Facile and continuous synthesis of graphene nanoflakes in RF thermal plasma
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Laboratory investigation of graphene modified asphalt efficacy to pavement performance
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Applications of Graphene-based Materials in Chromatography and Sample Preparation: A Review
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Edgewise Compressive Behavior of Composite Structural Insulated Panels with Magnesium Oxide Board Facings
PublicationEdgewise compression response of a composite structural insulated panel (CSIP) with magnesium oxide board facings was investigated. The discussed CSIP is a novel multifunctional sandwich panel introduced to the housing industry as a part of the wall, floor, and roof assemblies. The study aims to propose a computational tool for reliable prediction of failure modes of CSIPs subjected to concentric and eccentric axial loads. An advanced...
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Structure and thermoelectric properties of Bi–Te alloys obtained by novel method of oxide substrates reduction
PublicationA novel method of thermoelectric materials fabrication has been developed. Oxide reagents have been melted at high temperature in air, quenched, milled to powder and reduced in hydrogen to form Bi–Te alloys. Structural and thermoelectric properties of samples have been investigated depending on initial composition and temperature of reduction process. Sample 25Bi2O3–75TeO2 reduced at 340 °C for 10 h has been found to be a p-type...
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Flame retardant epoxy/halloysite nanotubes nanocomposite coatings: Exploring low-concentration threshold for flammability compared to expandable graphite as superior fire retardant
PublicationEpoxy nanocomposites containing halloysite nanotubes (HNTs) were developed and their low-concentration thresholds for thermal stability and flame retardancy were compared with that of epoxy system containing expandable graphite (EG), as a reference with superior flame retardancy. The effects of HNTs and EG on the peak of Heat Release Rate (pHRR), Total Heat Release (THR), and Time-To-Ignition (TTI) of the prepared samples were...
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Femtosecond laser ablated trench array for improving performance of commercial solid oxide cell
PublicationThe performance of electrode-supported solid oxide cells (SOCs) is limited adversely by gas diffusion impedance in thick and porous support. This work focuses on the improvement of gas transport properties of commercial Ni-YSZ anode-supported SOFC by femtosecond laser-based micromachining where micro-holes of identical depth but different hole separations pitches with minimal heated affected zones were imposed. The polarization...
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Development of iron doped strontium titanates as oxygen electrode for solid oxide fuel cells
PublicationProducing efficient solid oxide fuel cells (SOFC) without the use of harmful elements is one of the current challenges. Increasing the safety of people and reducing production costs is possible, among others, thanks to the use of iron doped strontium titanates as porous oxygen electrodes. In this thesis, the results of research on iron doped strontium titanates as potential oxygen electrodes for SOFC are presented. The research...
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Trimethylamine N-oxide and the reverse cholesterol transport in cardiovascular disease: a cross-sectional study
PublicationThe early atherosclerotic lesions develop by the accumulation of arterial foam cells derived mainly from cholesterol-loaded macrophages. Therefore, cholesterol and cholesteryl ester transfer protein (CETP) have been considered as causative in atherosclerosis. Moreover, recent studies indicate the role of trimethylamine N-oxide (TMAO) in development of cardiovascular disease (CVD). The current study aimed to investigate the association...
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Electrochemical determination of nitroaromatic explosives at boron-doped diamond/graphene nanowall electrodes: 2,4,6-trinitrotoluene and 2,4,6-trinitroanisole in liquid effluents
PublicationThe study is devoted to the electrochemical detection of trace explosives on boron-doped diamond/graphene nanowall electrodes (B:DGNW). The electrodes were fabricated in a one-step growth process using chemical vapour deposition without any additional modifications. The electrochemical investigations were focused on the determination of the important nitroaromatic explosive compounds, 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitroanisole...
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Actions of a nitric oxide donor on prostaglandin production and angiogenic activity in the equine endometrium
PublicationNitric oxide (NO) plays an important role in prostaglandin secretion and angiogenesis in the reproductive system. In the present study, the roles of the NO donor spermine NONOate and tumour necrosis factor-alpha (TNF; as a positive control) in prostaglandin production and angiogenic activity of equine endometria during the oestrous cycle were evaluated. In addition, the correlation between NO production...
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Preparation of Hydrogen Electrodes of Solid Oxide Cells by Infiltration: Effects of the Preparation Procedure on the Resulting Microstructure
PublicationIn this work, the infiltration technique was used to produce hydrogen electrodes for solid oxide cells. Different infiltration methodologies were tested in order to try to shorten the infiltration cycle time. The porous scaffolds used for infiltration were based on highly porous yttria-stabilized zirconia (YSZ) obtained by etching the reduced nickel from the Ni-YSZ cermet in HNO3 acid. The support had a complex structure which...
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Fabrication of Bi6Fe2Ti3O18 Ceramics by Mixed Oxide Method
PublicationIn the present study Bi6Fe2Ti3O18 (BFTO) ceramics has been fabricated by solid state reaction from the mixture of simple oxides viz. Bi2O3, TiO2 and Fe2O3. Stoichiometric mixture of the powders was thermally analyzed so parameters of the thermal treatment were determined. The EDS measurements have shown conservation of the chemical composition of the ceramic powder after calcination. Hot-pressing method was used for final densification...