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Wyniki wyszukiwania dla: YTTRIUM-DOPED STRONTIUM TITANATE
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Exsolution of Ni nanoparticles on the surface of cerium and nickel co-doped lanthanum strontium titanate as a new anodic layer for DIR-SOFC. Anti-coking potential and H2S poisoning resistance of the prepared material
PublikacjaThe aim of this study was to evaluate a new catalytic material for biogas fueled DIR-SOFC. This material was a perovskite-type SrTiO3 doped with La, Ce and Ni of a general formula La0.27Sr0.54Ce0.09Ni0.1Ti0.9O3-σ (LSCNT). Additional preparation steps were undertaken to promote a nickel exsolution process. Heat post-treatment of powders in a humidified H2 resulted in an intensive growth of nickel nanoparticles (NPs) while the temperature...
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Reduction of the strontium titanate doped by Ytrium ceramics observed by X-ray photoemission spectroscopy method
Dane BadawczeYtrium-doped strontium titanate (YSTF) ceramics materials were manufactured by three various methods: 1) standard solid-state reaction method from Y2O3 (Sigma Aldrich, 99,9%), TiO2 (Sigma Aldrich, 99%) and SrCO3 (Sigma Aldrich,98%), 2) Pechini method, 3) wet method.
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3 perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Microstructural and electrical properties of Y0:07Sr0:93−xTiO3− perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Structural and Transportation Properties of Strontium Titanate Composites with Ion Conductive Oxides
PublikacjaThis paper has been written based on the author’s doctoral dissertation “Structural and transportation properties of strontium and titanate composites with ion conductive oxides”, prepared under the supervision of Prof. Dr. Hab. Eng. Bogusław Kusz at the Department of Solid State Physics of Gdańsk University of Technology. It reports the idea of the thesis and conclusions from the study. Niobium doped strontium titanate (Sr(Ti,Nb)O3)...
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XPS analysis of strontium titanate ceramics
Dane BadawczeThe chemical composition of the strontium titanite doped with yttrium and iron ceramic samples was investigated. Samples of Y0.07Sr0.93Ti0.8Fe0.2 were prepared by solid phase reaction and sintered for 24 and 48 hours. Chemical composition was measured by UHV OmicronNanotechnology XPS system. The analysis confirmed the chemical composition of the ceramics...
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Synthesis and properties of porous Sr 0.96 Y 0.04 Ti 1−x Nb x O 3
PublikacjaA series of porous, single phase Sr0.96Y0.04Ti1-xNbxO3 samples was obtained using a wet synthesis method (modified citrate sol-gel) method. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) measurements have shown high stability of the obtained material in variable (oxidizing/reducing) atmospheres. All samples exhibit high conductivity in hydrogen atmosphere with the highest value (around 1S/cm)...
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XPS study of the YST ceramics
Dane BadawczeYttrium-doped strontium titanate was prepared via conventional solid-state reaction method from Y2O3 (Sigma Aldrich, 99,9%), TiO2 (Sigma Aldrich, 99%) and SrCO3 (Sigma Aldrich,98%). For comparision, two other techniques were used for synthesis: Pechini and wet methods. Both kind of samples were measured, after and before reduction process (in a hydrogen)....
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3-δ perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontiumtitanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work.It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent.Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry.The defect...
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Synthesis and structural properties of (Y, Sr)(Ti, Fe, Nb)O3−δ perovskite nanoparticles fabricated by modified polymer precursor method
PublikacjaThe yttrium, iron and niobium doped-SrTiO3 powders have been successfully fabricated by a modified low–temperature synthesis method from a polymer complex. The usage of strontium hydroxide precursor instead of conventional strontium nitrate or strontium carbonate provides to the possibility of significant decrease of annealing temperature. It allows to prepare a material with sphere-shape grains of nanometric size (15–70 nm). The...
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Fabrication and structural properties of Y and Fe co-doped SrTiO3 nanoceramics for SOFC
PublikacjaYttria and iron co-doped strontium titanate perovskites, (Y0,07Sr0,93Ti1-xFexO3-δx=0,1; 0,2) samples were fabricated by two methods: solid-state synthesis (SS) and the Pechinisol-gel modified method. The morphology of samples were measured by SEM and X-raydiffraction. Results were compared and discussed. The strong relationship between fabricationprocedure and microstructure has been proven. It was also observed, that the nanoceramicsobtained...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublikacjaNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Electrical and structural properties of Nb-doped SrTiO3
PublikacjaNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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Characterization methods of nickel nano-particles obtained by the ex-solution process on the surface of Pr, Ni-doped SrTiO3 perovskite ceramics
PublikacjaIn this paper, a novel electrode material based on Pr, Ni co-doped strontium titanate ( Sr0.7Pr0.3)xTi1−yNiyO3 with constant amount of 30% praseodymium dopant, different amount of nickel (y = 0.06 and y = 0.10) and additional nonstoichiometry in Sr-site (x = 1; x = 0.9 and x = 0.8) was investigated as fuel electrode for SOEC devices. A porous ceramics were prepared by solid-state reaction method. X-ray diffraction measurements...
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Structural and electrical properties of Cr-doped SrTiO 3 porous materials
PublikacjaSeries of single-phase materials with assumed formula SrTi1−xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery...
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The comparison of SrTi0.98Nb0.02O3–δ-CeO2 and SrTi0.98Nb0.02O3–δ-YSZ composites for use in SOFC anodes
PublikacjaComposites of Nb-doped strontium titanate mixed with yttria-stabilized zirconia or cerium oxide in 50:50, 70:30 and 85:15 weight ratios were evaluated as possible anode/electrolyte interface materials for solid oxide fuel cells in terms of chemical compatibility, electrical conductivity and mechanical properties. It has been shown that composite samples prepared by typical powder-mixing methods remain single-phase up to 1400°C....
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Structural Properties and Water Uptake of SrTi1−xFexO3−x/2−δ
PublikacjaIn this work, Fe-doped strontium titanate SrTi1−xFexO3−x/2−δ, for x = 0–1 (STFx), has been fabricated and studied. The structure and microstructure analysis showed that the Fe amount in SrTi1−xFexO3−x/2−δ has a great influence on the lattice parameter and microstructure, including the porosity and grain size. Oxygen nonstoichiometry studies performed by thermogravimetry at different atmospheres showed that the Fe-rich compositions...
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PVA-Based Films with Strontium Titanate Nanoparticles Dedicated to Wound Dressing Application
PublikacjaBioactive materials may be applied in tissue regeneration, and an example of such materials are wound dressings, which are used to accelerate skin healing, especially after trauma. Here, we proposed a novel dressing enriched by a bioactive component. The aim of our study was to prepare and characterize poly(vinyl alcohol) films modified with strontium titanate nanoparticles. The physicochemical properties of films were studied,...
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Development of iron doped strontium titanates as oxygen electrode for solid oxide fuel cells
PublikacjaProducing 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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Properties of Oxygen Vacancy and Hydrogen Interstitial Defects in Strontium Titanate: DFT + Ud,p Calculations
PublikacjaThis work presents extensive theoretical studies focused on the mixed ion-electron transport in cubic strontium titanate (STO). A new approach to the description of this difficult system was developed within the framework of linear-scaling Kohn–Sham density functional theory, as realized in the ONETEP program. The description we present is free of any empirical parameters and relies on the Hubbard U and Hund’s J corrections applied...
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Systematic Water Uptake Energetics of Yttrium-Doped Barium Zirconate—A High Resolution Thermochemical Study
PublikacjaA combination of surface area analyzer and microcalorimetry was employed to investigate the in situ water uptake energetics and the mechanism of proton incorporation in yttrium-doped barium zirconate in the temperature range 200–400 °C. The BaZr1–xYxO3 solid solutions are made with variable yttrium content (x = 10, 20, and 30 mol %) by a controlled oxidant-peroxo synthesis method. The water uptake increases as the partial pressure...
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Impedance spectroscopy of the lithium titanate doped by copper thin films
Dane BadawczeLithium titanate doped by copper thin films were derived by sol-gel method. Prepared gel was deposited by spin-coating technique. Samples with various content of Cu were measured by impedance spectroscopy method in a wide range of temperature, from -120 up to 150 deg.
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Structural and electrical properties of titanium-doped yttrium niobate
PublikacjaIn this work, the influence of the substitution of niobium by titanium in Y3Nb1-xTixO7-δ on the structural and electrical properties is reported. Several experimental techniques, i.e. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS), were applied to investigate the system Y3Nb1-xTixO7-δ. Titanium in Y3Nb1-xTixO7-δ is an acceptor-type...
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Dosimetric features of strontium orthosilicate (Sr2SiO4) doped with Eu2+
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XPS study of the lithium titanate doped by copper
Dane BadawczeLithium titanate doped by copper was measured by X-ray photoemission spectroscopy. For sol-gel synthesis lithium acetate dehydrate from Alfa Aesar GmbH &Co and titanium (IV) butoxide 97% from Aldrich were used as reagents. Copper (II) nitrate from Alfa Aesar was used as a source of Cu dopant. It was added in the proper weight to get an x index equal...
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Structure and transport properties of donor-doped barium strontium cobaltites
PublikacjaIn this work, Nb-substituted barium strontium cobaltites Ba0.5Sr0.5Co1-xNbxO3-δ (x = 0 – 0.4) have been fabricated and studied. The structural analysis showed that the Nb content influences the lattice constant as well as the distance between the (Co, Nb) and oxygen atoms. The study of morphology of samples showed that the Nb content does not change the porosity, grain size and morphology of the ceramics. The total electrical conductivity...
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DSC and TG results for strontium ferrite molybdate: pristine La, or Nb-doped
Dane BadawczeThis dataset consists of DSC and TG data collected for SFM, LSFM (La-doped) and SFMNb (Nb-doped) compounds, which were undertaken to analyze the reoxidation process of reduced compounds and its transition to double-perovskite structure .The appropriate amount of the powder (~10 mg with 10% tolerance factor) were placed into the alumina crucible and...
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Investigation methods of ionic conductivity measurements in polycrystalline MIEC (mixed ionic-electronic conductor) based on perovskite ceramics
PublikacjaPaper about the measurements of ionic conductivity in LSM and strontium titanate ceramics.
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Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3-delta SOFC anodes
PublikacjaIn order to find a relationship between structural and electrical properties, niobium and yttrium doped SrTiO3 ceramics were prepared via solid-state reaction. The samples were sintered in hydrogen and air conditions. The samples were also fabricated with a pore-former to obtain highly porous specimens. The electrical properties of Nb-doped SrTiO3 samples and yttrium and niobium co-doped SrTiO3 were compared. The comparable electrical...
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Conductivity, structure, and thermodynamics of Y2Ti2O7–Y3NbO7 solid solutions
PublikacjaThe defect fluorite yttrium niobate Y3NbO7 and pyrochlore yttrium titanate Y2Ti2O7 solid solutions have been synthesized via a solid state synthesis route. The resulting stoichiometry of the oxides is Y2+xTi2−2xNbxO7, where x = 0 to x = 1. All of the samples were single-phase; however, for those with a predominant fluorite phase, a small amount of additional pyrochlore phase was detected. The volume of the solid solution unit cells...
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Study of the Layer-Type BST Thin Film with X-ray Diffraction and X-ray Photoelectron Spectroscopy
PublikacjaIn the present paper, results of X-ray photoelectron studies of electroceramic thin films of barium strontium titanate, Ba1xSrxTiO3 (BST), composition deposited on stainless-steel substrates are presented. The thin films were prepared by the sol-gel method. A spin-coating deposition of BST layers with different chemical compositions was utilized so the layer-type structure of (0-2) connectivity was formed. After the deposition,...
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Optical measurements of LTO:Cu sol-gel derived thin films
Dane BadawczeLithium titanate doped by copper thin films were manufactured by chemical, sol-gel method. Flms were deposited on a Corning glass substrated by spin coater. To calculated optical band gap and other optcal parameters, UV-VIS spectroscopy measurements were performed. For measurements selected samples with various content of Cu.
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Morphology of the sol-gel derived LTO:Cu films
Dane BadawczeMorphology of the lithium titanate doped by Cu thin films were investigated by SEM microscope. Films were deposited by spin-coater from sol-gel derived sol. SEM images showed a high porous structure, tipaciall for sol-gel based films. For measurements samples with a various content of Cu were selected.
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Structural investigations of the LTO:Cu thin films
Dane BadawczeLithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure was characterized by X-ray Diffraction (XRD). All samples revealed presence of LTO spinel phase. X-ray pattern of undoped LTO was free of any impurities and other crystal phases. Similarly, samples with low amount of copper dopant (x = 0.05...
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SEM images of SFM, LSFM and SFMNb in as-prepared state and reduced
Dane BadawczeThis dataset contains SEM images taken for pristine strontium ferrite molybdate, as well as ones doped with lanthanum or niobium. Materials were characterized in powder, under high vacuum in secondary electron mode. The images are divided into folders for as-prepared samples and reduced (H2, 800 deg, 4 h) ones.
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A white phosphor based on oxyfluoride nano-glass-ceramics co-doped with Eu3+ and Tb3+: Energy transfer study
PublikacjaStrontium fluoride nanocrystals doped separately with Ln3+ = Eu3+ or Tb3+ ions (95SrF2·5LnF2), as well as co-doped with both the ions (95SrF2·Eu4Tb) were synthesized for comparison. Then, glass-ceramics consisting of the mono-doped or di-doped SrF2 nanocrystals incorporated into amorphous silica (90SiO2·9.5SrF2·0.5Ln or 90SiO2·9.5SrF2·0.1EuF3·0.4Tb) were prepared by sol-gel procedure. The studied materials were characterized by...
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The electrical conductivity of pristine, La-, and Nb-doped SFM measured in air and hydrogen atmospheres
Dane BadawczeThis dataset consists of an Excel sheet with the result of DC4W method of electrical measurements. The measurements were conducted on pristine strontium ferrite molubdate as well as ones doped with La and Nb. Additionally two samples co-doped with La and Ni/Co were analyzed. Pellets were prepared by high temperature sintering at 1400 deg. C, then cut...
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The XAS spectra of O-K edges, Fe-L edges in pristine, La-, and Nb-doped SFM in 3 states: as-prepared, reduced and reoxidized
Dane BadawczeThis dataset contains the normalized and exported to *.txt spectra for x-ray absorption spectroscopy. The samples analyzed were strontium ferrite molybdate based, doped with lanthanum and niobium. The powders were measured in as-prepared state (denoted in filename as AP), reduced (red) and reoxidized (reox). The filenames are written accordingly: Edge_(optional:...
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Water uptake and energetics of the formation of barium zirconate based multicomponent oxides
PublikacjaA group of multi-component oxides based on BaZrO3 have been prepared using a solid-state reaction method and examined in terms of their water uptake and thermodynamics of formation. Depending on the type and amount of acceptor substitution, the synthesized compounds exhibit various proton defect concentrations, reaching up to 0.2 mol/mol for a compound containing 10 different elements in the B-sublattice, where 50% of them are...
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Fabrication and Crystal Structure of Sol-Gel Deposited BST Thin Films with Compositional Gradient
PublikacjaIn the present research technology of compositionally graded barium strontium titanate Ba1-xSrxTiO3 thin films deposited on stainless steel substrates by sol-gel spin coating followed with thermal annealing at T = 650°C is reported. Results of thermal behavior of the sol-gel derived powders with compositions used for fabrication of graded structure (i.e. with Sr mole fraction x = 0.5, 0.4 and 0.3) are described. X-ray diffraction...
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From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions
PublikacjaGlass-ceramics with the composition B2O3 -Bi2O3 -SrF2 were synthesized by the conventional melt-quenching technique and subsequent crystallization of the parental glasses. The temperature at which the ceramization was carried out was selected based on differential scanning calorimetry (DSC) analysis. The structure of the studied materials and the formation of SrF2 nanocrystals were confirmed by the Fourier-transform infrared spectroscopy...
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INFLUENCE OF CERAMIC COATING ON MECHANICAL PROPERTIES OF STAINLESS STEEL
PublikacjaCrystal structure and phase composition of stainless steel substrates (AISI 304 type) was studied and it was found that they adopted the cubic symmetry. The calculated elementary cell parameter for the mayor Fe-Ni phase (weight fraction 99%) was a = 3.593 Å, whereas the mean grain size was = 2932 Å. Morphology of the stainless steel substrate surface was studied with profilometry. Mechanical properties of the stainless steel...
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Interaction of SrTi0.65Fe0.35O3-δ with LaNi0.6Fe0.4O3-δ, La0.6Sr0.4Co0.2Fe0.8O3-δ and Ce0.8Gd0.2O2-δ
PublikacjaIron doped strontium titanates SrTi1-xFexO3-δ are perovskites of versatile properties. They can be used in solid oxide fuel cells or high temperature oxygen sensors. Their reactivity with electrolyte materials, cathode buffer layer materials, other cathode materials or current collector layers has not been fully tested. In this study we use X-ray diffraction to check SrTi0.65Fe0.35O3-δ compatibility with Ce0.8Gd0.2O2-δ (used as...
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High-temperature properties of titanium-substituted yttrium niobate
Publikacjahe defect fluorite titanium-doped yttrium niobate samples Y3Nb1−xTixO7−δ have been synthesized and investigated by the means of high-temperature X-ray diffraction, dilatometry, and thermogravimetry. Thermal expansion coefficients (TECs) as well as chemical expansion coefficients for material with 5, 10, and 15 mol% of titanium were determined. All investigated samples exhibit chemical contraction caused by Ti doping. The values...
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Measurements of the chemical composition of LTO:Cu powders
Dane BadawczeLithium titanate doped by copper was measured by X-ray photoemission spectroscopy (XPS). For sol-gel synthesis lithium acetate dehydrate and titanium (IV) butoxide 97% and copper (II) nitrate from Alfa Aesar were used as a reagents. Cu precursor was added in the proper weight to get an x index equal 0, 0.1 and 0.2. In the first step lithium acetate...
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Lanthanide ions (Eu3+, Er3+, Pr3+) as luminescence and charge carrier centers in Sr2TiO4
PublikacjaA series of strontium orthotitanate (Sr2TiO4) samples doped with 2% of a mole of europium, praseodymium, and erbium were obtained using the solid-state synthesis method. The X-ray diffraction (XRD) technique confirms the phase purity of all samples and the lack of the influence of dopants at a given concentration on the structure of materials. The optical properties indicate, in the case of Sr2TiO4:Eu3+, two independent emission...
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The luminescence study of Sr2TiO4:Sm3+ coumpounds.
Dane BadawczeA luminescent material based on the strontium orthotitanate (Sr2TiO4) matrix doped with 1% of a mole of samarium was obtained using the typical solid-state synthesis method under a neutral atmosphere of nitrogen. The sample was investigated using powder X-ray diffraction (XRD) and several luminescence techniques to study the phase composition, luminescence...
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X-Ray photoemission spectroscopy measurements of the Nb-V-Sr-O ceramics
Dane BadawczeNiobium doped strontium vanadate based perovskite SrV1-xNbxO3-δ materials were prepared via conventional solid state reaction (SSR) method. For comparison, different samples with a various amount of niobium dopant in the structure were synthesized; x = 0; 0,2; 0,5; 0,8 and 1. Samples were sintered by two-steps: first under a pure hydrogen (purity >99.999%)...
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Two kinds of oxygen vacancies in lithium titaniate doped with copper as detected by EPR
PublikacjaLithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure and morphology are characterized by X-ray Diffraction (XRD), X-ray Photoemission Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). Spin Hamiltonian parameters describing Zeeman and hyperfine interaction for 63Cu2+ ions were obtained from EPR spectra simulations. The spectra...
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Synergistic effects of nitrogen-doped carbon and praseodymium oxide in electrochemical water splitting
PublikacjaHybrid materials featuring perovskite-type metal oxide in conjunction with heteroatom-doped graphene hold immense promise as alternatives to costly noble metal catalysts for electrochemical water splitting, facilitating the generation of environmentally friendly hydrogen. In this study, perovskite-type oxide containing praseodymium, barium, strontium, cobalt, and iron atoms dispersed in a carbon matrix as a catalyst is synthesized...