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Wyniki wyszukiwania dla: doping control
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A- and B-site doping effect on physicochemical properties of Sr2−xBaxMMoO6 (M = Mg, Mn, Fe) double perovskites — candidate anode materials for SOFCs
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Tuning Cu-Content La1−xSrxNi1−yCuyO3−δ with Strontium Doping as Cobalt-Free Cathode Materials for High-Performance Anode-Supported IT-SOFCs
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Modification of Ruddlesden-Popper-type Nd2-xNi0.75Cu0.2M0.05O4±δ by the Nd-site cationic deficiency and doping with Sc, Ga or In: Crystal structure, oxygen content, transport properties and oxygen permeability
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Boron-doped carbon nanowalls for fast and direct detection of cytochrome C and ricin by matrix-free laser desorption/ionization mass spectrometry
PublikacjaDetecting proteins via surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) method is still highly challenging, and only few examples of nanomaterials have been demonstrated to perform such detection so far. In this study, carbon nanowalls (CNWs), vertically aligned graphene sheet-based materials, presenting specific morphology, dimensions, and boron doping levels have shown improved performances for both qualitative...
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The influence of polarization of titania nanotubes modified by a hybrid system made of a conducting polymer PEDOT and Prussian Blue redox network on the Raman spectroscopy response and photoelectrochemical properties
PublikacjaIn this work we show the impact of applied potential on network vibrations and photoelectrochemical properties of a composite material containing hydrogenated titania nanotubes and poly (3,4-ethylenedioxythiophene) with iron hexacyanoferrate (H-TiO2/pEDOT:Fehcf) acting as a redox centre. For this purpose, Raman spectroscopy measurements under the working electrode (WE) polarization were carried out, allowing investigation of changes...
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A rapid and sensitive method for the quantitative analysis of ibuprofen and its metabolites in equine urine samples by gas chromatography-tandem mass spectrometry
PublikacjaIbuprofen is widely used in human and veterinary medicine for the treatment of chronic pain as well as rheumatic and musculoskeletal disorders. However, t he anal- gesic and anti-inflammatory properties of Ibuprofen have contributed to frequent drug abuse in equestr ian s ports. A sensitive and rapid gas chromatography with tandem mass spectrometry based method with a simple liquid-liquid extraction and deriva- tization requiring...
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Physical properties of polyazomethine thin films doped with iodine
PublikacjaPurpose: The aim of this paper is to show influence of doping 1,4-phenylene-methylenenitrilo-1,4-phenylenenitrilomethylene (PPI) with iodine and to propose doping mechanism and its impact on electronicstructure of doped PPI thin films.Design/methodology/approach: Influence of iodine doping on electronic structure of polyazomethine thinfilms was investigated. Optical absorption spectra, XRD spectra and AFM images of doped PPI...
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Praseodymium substituted lanthanum orthoniobate: Electrical and structural properties
PublikacjaThe results of ionic transport and structural measurements for the lanthanum orthoniobate doped by praseodymium are presented and discussed. The influence of calcium co-doping on these properties has also been analyzed. The results suggest the predominant protonic conductivity for the investigated system in the whole range of investigated temperatures. The influence of calcium co-doping on phase purity is analyzed.
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Electrophoretic co-deposition of Fe2O3 and Mn1,5Co1,5O4: Processing and oxidation performance of Fe-doped Mn-Co coatings for solid oxide cell interconnects
PublikacjaThe “in-situ” Fe-doping of the manganese cobalt spinel was achieved by electrophoretic co-deposition of Mn1,5Co1,5O4 and Fe2O3 powders followed by a two-step reactive sintering treatment. The effects on the coating properties of two different Fe-doping levels (5 and 10 wt.% respectively) and two different temperatures of the reducing treatment (900 and 1000 °C) are discussed. Samples with Fe-doped coatings demonstrated a lower...
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Tailoring Electro/Optical Properties of Transparent Boron-Doped Carbon Nanowalls Grown on Quartz
PublikacjaCarbon nanowalls (CNWs) have attracted much attention for numerous applications in electrical devices because of their peculiar structural characteristics. However, it is possible to set synthesis parameters to vary the electrical and optical properties of such CNWs. In this paper, we demonstrate the direct growth of highly transparent boron-doped nanowalls (B-CNWs) on optical grade fused quartz. The effect of growth temperature...
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Microstructure and Electrical Properties of Fe,Cu Substituted (Co,Mn)3O4 Thin Films
PublikacjaIn this work, thin films (~1000 nm) of a pure MnCo2O4 spinel together with its partially substituted derivatives (MnCo1.6Cu0.2Fe0.2O4, MnCo1.6Cu0.4O4, MnCo1.6Fe0.4O4) were prepared by spray pyrolysis and were evaluated for electrical conductivity. Doping by Cu increases the electrical conductivity, whereas doping by Fe decreases the conductivity. For Cu containing samples, rapid grain growth occurs and these samples develop cracks...
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Absence of superconductivity in fluorine-doped neptunium pnictide NpFeAsO
PublikacjaX-ray diffraction, specific heat, magnetic susceptibility and inelastic x-ray scattering measurements on the transurarium oxypnictides NpFeAsO and NpFeAsO0.85F0.15 are presented. No superconductivity down to 2 K was observed upon fluorine doping, contrary to the structurally analogous rare-earth pnictides. No modification of the phonon density of states was observed upon doping with fluorine. We discuss our results in light of...
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Niobiany ziem rzadkich - właściwości i zastosowania
PublikacjaRare earth niobates are a very interesting group of materials. These compound have different properties which could be changes in a wide range by appropriate doping. X-Ray diffraction examinations for some compounds of RE3NbO7 group were shown
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Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
PublikacjaThe formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at...
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Electrophoretic co-deposition of Mn1.5Co1.5O4, Fe2O3 and CuO: Unravelling the effect of simultaneous addition of Cu and Fe on the microstructural, thermo-mechanical and corrosion properties of in-situ modified spinel coatings for solid oxide cell interconnects
PublikacjaA systematic microstructural, thermo-mechanical and electrical characterization of simultaneous Fe–Cu doped Mn–Co spinel coatings processed by electrophoretic co-deposition on Crofer 22 APU is here reported and discussed. An innovative approach for the simultaneous electrophoretic deposition of three spinel precursors is designed, conceived and optimised, with the aim of outlining time- and energy-saving spinel modification routes....
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Quantification of unconjugated and total ibuprofen and its metabolites in equine urine samples by gas chromatography–tandem mass spectrometry: Application to the excretion study
PublikacjaIbuprofen (IBU) is a widely used nonsteroidal anti-inflammatory drug (NSAID) in human and also veterinary medicine. NSAIDs are usually highly metabolized compounds in horses; they are often present in equine urine, mostly in their conjugated forms (glucuronides). Thus, hydrolysis to cleave the glucuronide linkage prior to anti-doping analysis is often necessary for improving detection. In this study, unconjugated and total IBU...
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Enhanced photoelectrochemical and photocatalytic performance of iodine-doped titania nanotube arrays
PublikacjaThe paper discusses the synthesis and performance of iodine doped titania nanotube arrays exhibited under irradiation. The doping procedure was performed as an additional, electrochemical process carried out after formation of nanotube arrays via anodization of Ti substrate. The optical and structural properties were characterized using Raman, UV-vis, photoluminescence and X-ray photoelectron spectroscopy. The surface morphology...
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Electrochemical Activity and Electrical Properties of Optimized Polypyrrole Coatings on Iron
PublikacjaIn this work, electrochemical activity and electrical properties of polypyrrole (PPy) coated iron electrodes have been investigated. PPy film was electrochemically polymerized from sodium salicylate aqueous solution under conditions, which provided an increase of iron corrosion resistance. It was noticed that the pH of the solution and the applied electrode potential range during the study of the polymer properties had an influence...
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Electrochemical oxidation of landfill leachate using boron-doped diamond anodes: pollution degradation rate, energy efficiency and toxicity assessment
PublikacjaElectrochemical oxidation (EO), due to high efficiency and small carbon footprint, is regarded as an attractive option for on-site treatment of highly contaminated wastewater. This work shows the effectiveness of EO using three boron-doped diamond electrodes (BDDs) in sustainable management of landfill leachate (LL). The effect of the applied current density (25–100 mA cm−2) and boron doping concentration (B/C ratio: 500 ppm, 10,000...
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Superconductivity in the Cu(Ir1-xPtx)2Se4 spinel
PublikacjaWe report the observation of superconductivity in the CuIr2Se4 spinel induced by partial substitution of Pt for Ir. The optimal doping level for superconductivity in Cu(Ir1-xPtx )2Se4 is x = 0.2, where Tc is 1.76 K. A superconducting Tc vs composition dome is established between the metallic, normal conductor CuIr2Se4 and semiconducting CuIrPtSe4. Electronic structure calculations show that the optimal Tc occurs near the electron count...
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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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Modelling of Graphene Field-Effect Transistor for lectronic sensing applications
PublikacjaA top-gated Graphene Field-Effect Transistor (GFET) suitable for electronic sensing applications was modelled. The applied simulation method reproduces correctly the output transfer GFET characteristics and allows to investigate doping effect caused by different physical, chemical or biological factors. The appearance of additional charge in the system results in the shift of the current-voltage characteristic. This feature could...
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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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In-situ Cu-doped MnCo-spinel coatings for solid oxide cell interconnects processed by electrophoretic deposition
PublikacjaThe Cu doping of the Mn–Co spinel is obtained “in-situ” by electrophoretic co-deposition of CuO and Mn1.5Co1.5O4 powders and subsequent two-step reactive sintering. Cu-doped Mn1.5Co1.5O4 coatings on Crofer22APU processed by electrophoretic co-deposition method are tested in terms of long term oxidation resistance and area specific resistance tests up to 3600 h. The introduction of Cu in the spinel lead to higher level of densification...
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Effects of Na+, K+ and B3+ Substitutions on the Electrical Properties of La10Si6O27 Ceramics
PublikacjaDoping of Na and K at La sites and of B at Si site in La10Si6O27 with oxyapatite structure and fabrication of their ceramics were made by the solid-state reaction method. It was found that partial substitution of Na+ and K+ on La sites decreased the sinterability of the La10Si6O27 based ceramics, whereas partial substitution of B3+ on the Si site improved the sinterability. Na+ and K+ substitutions in La10−xNaxSi6O27−x and La10−xKxSi6O27−x...
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Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublikacjaIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
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Iron doped manganese cobaltite spinel coatings produced by electrophoretic co-deposition on interconnects for solid oxide cells: Microstructural and electrical characterization
PublikacjaWe report a systematic microstructural and electrical characterization of iron doped Mn–Co spinel coatings processed by electrophoretic co-deposition of Mn1.5Co1.5O4 and Fe2O3 powders on Crofer 22 APU and AISI 441 steel substrates. Iron addition to Mn–Co spinel coating leads to a reduction of the area specific resistance on both substrates, after 3200 h at 750 °C. The Fe doped Mn–Co coating both leads to a thinner oxide scale and...
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Thin layer of ordered boron-doped TiO2 nanotubes fabricated in a novel type of electrolyte and characterized by remarkably improved photoactivity
PublikacjaThis paper reports a novel method of boron doped titania nanotube arrays preparation by electrochemical anodization in electrolyte containing boron precursor – boron trifluoride diethyl etherate (BF3 C4H10O), simultaneously acting as an anodizing agent. A pure, ordered TiO2 nanotubes array, as a reference sample, was also prepared in solution containing a standard etching compound: ammonium fluoride. The doped and pure titania...
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Electrochemical oxidation of PFOA and PFOS in landfill leachates at low and highly boron-doped diamond electrodes
PublikacjaPolyfluorinated alkyl substances (PFASs) may reach landfill leachates (LLs) due to improper waste management. In this study perfluorooctanoate (PFOA) and perfluorooctane sulphonate (PFOS) were used as representatives of PFASs in the decomposition on boron-doped diamond electrodes (BDDs) with high (10k ppm) and low (0.5k ppm) boron doping concentrations. The result shows that although better COD removal efficacies are obtained on...
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Oxide nanoparticle exsolution in Lu-doped (Ba,La)CoO3
PublikacjaThis study investigated Lu doping of Ba0.5La0.5CoO3 and its influence on the exsolution of oxide nanoparticles (NPs). As a result of Lu doping, we observed the phase segregation into the main Ba0.4La0.6Co0.85Lu0.15O3 (BLCO–Lu) phase and the secondary Ba0.85La0.15Co0.75Lu0.25O3 (BCO–Lu) phase. We noticed the exsolution of BCO–Lu nanoparticles on the main BLCO–Lu phase. Moreover, the BLCO–Lu phase exsolved in the form of nanoparticles...
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Optical properties of boron-doped nanocrystalline diamond films studied by spectroscopic ellipsometry
PublikacjaThe optical properties of boron-doped nanocrystalline diamond films, coated using Microwave Plasma Enhanced Chemical Vapour Deposition (μPE CVD) system, were analyzed by spectroscopic ellipsometry. Diamond films were deposited on silicon substrates. The ellipsometry data (refractive index (n(λ)), extinction coefficient (k(λ)) were modeled using dedicated software. Evolution of the optical structure with boron doping was observed...
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Facile preparation of extremely photoactive boron-doped TiO2 nanotubes arrays
PublikacjaDoping of TiO2 nanotube arrays with boron was realized via electrochemical treatment of as-anodized titania immersed in electrolyte containing boric acid. The photoactivity of doped and pure titania was examined by means of photoelectrochemical and photocatalytic response under UV-vis irradiation. The results showed that photocurrent density of B-TNTs is remarkably higher (7.5 times) than density of pure TiO2 nanotube arrays. Furthermore,...
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In-situ optical diagnostics of boron-doped diamond films growth
PublikacjaInterferometry is a desirable method for in-situ measurement of thin, dielectric film growth, as it don't modify conditions of film deposition. Here we present interferometrical measurements of thickness of doped diamond films during Chemical Vapor Deposition (CVD) process. For this purpose we used a semiconductor laser with a 405nm wavelength. Additional ex-situ measurement using spectral interferometry and ellipsometry...
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Characteristics of LaCo 0.4 Ni 0.6-x Cu x O 3-δ ceramics as a cathode material for intermediate-temperature solid oxide fuel cells
PublikacjaIn this study, the effects of Cu-ion substitution on the densification, microstructure, and physical properties of LaCo0.4Ni0.6-xCuxO3-δ ceramics were investigated. The results indicate that doping with Cu ions not only enhances the densification but also promotes the grain growth of LaCo0.4Ni0.6-xCuxO3-δ ceramics. The Cu substitution at x ≤ 0.2 can suppress the formation of La4Ni3O10, while the excess Cu triggers the formation...
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Electrochemically Induced Synthesis of Triphenylamine-based Polyhydrazones
PublikacjaTriphenylamine-based hydrazones were subjected to electropolymerization process that gave well conductive hydrazone based polymers. The first example of polyhydrazone formation during the electrochemical process was shown. The estimation of polymer structure was demonstrated using IR spectroelectrochemistry. The EPR spectroelectrochemistry allowed to explain why in some cases dimer couldn’t be formed. The results of electrochemical,...
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Electrical conductivity of nanostructured acceptor-doped ceria fabricated by spark plasma sintering (SPS)
PublikacjaHigh purity nanoscale powders (~10–15 nm size) of two different compositions of ceria, doped with Gd3+ and Ca2+, have been consolidated by spark plasma sintering (SPS) at different temperatures. Fully-dense samples were observed only at a sintering temperature of 980 °C. The as-sintered samples showed rather fast grain growth with an average grain size below 300 nm. The electrical properties of the samples were evaluated by impedance...
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Influence of Sb-substitution on ionic transport in lanthanum orthoniobates
PublikacjaThe results of ionic transport measurements for the lanthanum orthoniobate substituted with 10 and 30 mol% of antimony (LaNb0.9Sb0.1O4 and LaNb0.7Sb0.3O4) are presented and discussed. The influence of calcium co-doping on these properties has also been analysed. It has been shown that for the investigated material protonic conductivity predominates at temperatures up to 800 °C in oxidizing atmospheres under wet conditions. The...
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SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NIOBIUM-DOPED HYDROXYAPATITE CERAMICS
PublikacjaHydroxyapatite (HAp) ceramic materials are considered as one of the most promising implant materials in bone surgery and in dentistry. They exhibit unique biocompatibility, bioactivity, and osteoconductivity, which are the most desirable biomaterial features. However, HAp itself is brittle, has low strength, high degree of crystallinity and low solubility at physiological pH. Doping synthetic HAp with metal ions plays an important...
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Structure and optical parameters of Eu doped tellurium oxide thin films prepared by reactive magnetron sputtering method
PublikacjaIn this work the structural properties and photoluminescence of tellurium dioxide thin films doped by europium were described. Thin films were deposited by magnetron sputtering method and simultaneously heated at 200 °C. Presence of Eu ions and their valence states was confirmed by X-ray photoemission spectroscopy measurements. The structure of the films as well as the influence of europium dopant on crystalline structure of the...
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Superconductivity and ferromagnetism in Pd doped Y9Co7
PublikacjaThe ferromagnetic superconductor Y9Co7 was chemically doped to yield the solid solution Y9Co7-xPdx for 0 < x < 0.4. The lattice parameter a does not depend on x, whereas c increases with increasing Pd content up to x ¼ 0.2, the palladium solubility limit. The transition from ferromagnetism (TC ¼ 4.25 K) to superconductivity (Tsc ¼ 2.4 K) was observed only for the parent Y9Co7 compound. For the lowest tested Pd doping level (x ¼...
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The effect of Sr and Mg substitutions on structure, mechanical properties and solubility of fluorapatite ceramics for biomedical applications
PublikacjaIonic substitutions play important role in the modifications of biological apatites. Recently, attention has been focused on the co-doping effects on the functional properties of apatite-based biomaterials. In this research work, the dense samples of fluorapatites, Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2, were produced after sintering at 1250 °C for 6 h in air. Structural characterization carried out with XRD, IR, Raman and SEM, confirmed...
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Functionalization of graphene oxide coatings with phosphorus atoms and their corrosion resistance in sodium chloride environment
PublikacjaIn this work, we compared corrosion resistance of graphene oxide, and phosphorus functionalized reduced graphene oxide coatings obtained as a result of electrophoretic deposition on the copper substrate. Doping graphene oxide with phosphorus atoms was performed by a hydrothermal method in the presence of different amounts of phosphoric acid. Structural studies confirmed the insertion of phosphorus atoms into the graphene oxide...
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Structure and electric transport properties of Ca-doped bulk PrBa2Cu3O7−δ
PublikacjaThe crystal structure and electric transport properties of Pr1-xCaxBa2Cu3O7- delta (x= 0.0, 0.1, 0.2, 0.5) bulk ceramic samples, prepared by the standard solid-state reaction in air, were examined by X-ray power diffraction, resistivity measurements and room temperature thermoelectric power determination. Ca atoms introduce additional holes to the system as well as structural defects. The orthorhombic-to-tetragonal structural...
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Copper and cobalt co-doped ceria as an anode catalyst for DIR-SOFCs fueled by biogas
PublikacjaThe nanocrystalline compounds of Co and Cu co-doped ceria (with up to 20 mol.% of dopants) were fabricated by the reverse microemulsion synthesis method. They were deposited in a form of layers on the surface of SOFC anode in an aim to act as electrochemically active materials for biogas reforming process. Fourier Transformed Infrared Spectroscopy was used to analyze a composition of outlet gases simultaneously with the tests of...
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Luminescent properties of Ln3+ doped tellurite glasses containing AlF3
PublikacjaThe low-phonon energy tellurite glasses TeO2-BaO-Bi2O3 and TeO2-BaO-Bi2O3-AlF3 triply doped with Eu3+, Tb3+, Tm3+ ions in two different molar ratios were synthesized using melt-quenching technique. Their structure and luminescence properties were widely investigated by X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence Spectroscopy (PL). The luminescence...
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Effects of Na+, K+ and B3+ Substitutions on the Electrical Properties of La10Si6O27 Ceramics
PublikacjaDoping of Na and K at La sites and of B at Si site in La10Si6O27 with oxyapatite structure and fabrication of their ceramics were made by solid-state reaction method. It was found that partial substitution of Na+ and K+ on La sites decreased the sinterability of the La10Si6O27 based ceramics, whereas partial substitution of B3+ on Si site imporved the sinterability. Na+ and K+ substitutions in La10-xNaxSi6O27-x and La10-xKxSi6O27-x...
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KTaO3 a perovskite for water and air treatment
PublikacjaPerovskites are inorganic compounds that exhibit dielectric properties. These minerals belong to the crystal ceramics family. These compounds are described by the formula: ABX3 where, A and B are 2, 3 or 4 valuable metal ions, and X is an ion of oxygen or fluorine. An example of perovskite is the compound KTaO3. There are many methods for producing KTaO3, but the hydrothermal method is most commonly used. Perovskites can be characterized...
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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
PublikacjaIn 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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Spectroscopic studies of Nb-doped tricalcium phosphate glass-ceramics prepared by sol-gel method
PublikacjaCalcium-phosphate based glasses and glass-ceramics play a crucial role in the tissue engineering development. Apart from their high biocompatibility and excellent ability to undergo varying degrees of resorbability1, they exhibit relatively high bioactivity and due to that they are commonly used as bone and dental implants. A substantial research effort is devoted to improve calcium-phosphate materials physico-chemical properties...