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Search results for: PYROCHLORE OXIDES
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Stabilization of the pyrochlore phase of Mn2Sb2O7 by double substitution
PublicationPolycrystalline samples of (Ce4+Mn2+3)(Ga3+Sb5+3)O14 were synthesized by a high-temperature solid-state reaction. In contrast with the parent Mn2Sb2O7 compound that adopts a rhombohedral or monoclinic structure at T > 600 °C, the pyrochlore structure of CeMn3GaSb3O14 is retained up to at least T = 1070°C. High-resolution synchrotron x-ray diffraction measurements show no sign of a superstructure or distortion from cubic symmetry...
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Chemical Pressure Tuning Magnetism from Pyrochlore to Triangular Lattices
PublicationGeometrically frustrated lattices combined with magnetism usually host quantum fluctuations that suppress magnetic orders and generate highly entangled ground states. Three-dimensionally (3D) frustrated magnets generally exist in the diamond and pyrochlore lattices, while two-dimensionally (2D) frustrated geometries contain Kagomé, triangular, and honeycomb lattices. In this work, we reported using chemical pressure to tune the magnetism...
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Superconductivity in Bismuth Pyrochlore Lattice Compounds RbBi2 and CsBi2: The Role of Relativistic Effects
PublicationSuperconducting properties of two bismuthide intermetallic compounds, RbBi2 and CsBi2, were studied by means of experimental measurements and ab initio calculations. We show that in both compounds, the superconductivity emerges from the pyrochlore Bi lattice and its formation is heavily influenced by relativistic effects. Based on our analysis of the effect of spin–orbit coupling on the electron–phonon coupling, we suggest a possible...
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Electrical Transport and Magnetic Properties of Metal/Metal Oxide/Metal Junctions Based on Anodized Metal Oxides
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Electrical Transport and Magnetic Properties of Metal/Metal Oxide/Metal Junctions Based on Anodized Metal Oxides
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Fe-modified Mn2CuO4 spinel oxides: coatings based on abundant elements for solid oxide cell interconnects
PublicationThe current state of the art steel interconnect coating materials are based on critical raw material - Co-oxide spinels. Replacing Co-oxide spinels with alternative, abundant materials can reduce the dependence on the critical raw materials. Cobalt-free coatings with the general formula Mn2-xCuFexO4, where x = 0, 0.1, 0.3, were electrophoretically deposited on a ferritic stainless-steel support and evaluated. Prior to deposition,...
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Titanium lanthanum three oxides decorated magnetic graphene oxide for adsorption of lead ions from aqueous media
PublicationThe current study presents a viable and straightforward method for synthesizing titanium lanthanum three oxide nanoparticles (TiLa) and their decoration onto the ferrous graphene oxide sheets to produce FeGO-TiLa as efficient magnetic adsorbent. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibration sample magnetometer (VSM) were used to evaluate...
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Enthalpies of formation of rare earth niobates, RE3NbO7
PublicationHigh-temperature oxide melt solution calorimetry was used to investigate energetics of a series of rare earth niobates RE3NbO7. All of investigated compounds were found to be stable in enthalpy in respect to their oxides. The enthalpy of formation from oxides becomes more exothermic as the size of the RE cation increases, a trend seen previously in other RE compounds including pyrochlores, perovskites, and phosphates. For smaller...
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Direct conversion of secondary phosphine oxides and H-phosphinates with [di(acyloxy)iodo]benzenes to phosphinic and phosphonic amides
PublicationW publikacji przedstawiono metodę pozwalająca na bezpośrednie otrzymywanie amidów kwasu fosfinowego i fosfonowego w reakcji drugorzędowych tlenków fosfin lub H-fosfinianów z [di(acyloksy)iodo]benzenami w obecności amin pierwszo lub drugorzędowych. Wykorzytując silne acylujące właściwości układu [di(acyloksy)iodo]benzen/R2P(O)H.
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The effect of aluminium oxide on the reduction of cobalt oxide and thermostabillity of cobalt and cobalt oxide
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Charge Transport in High-Entropy Oxides
PublicationThis work presents the results of research on the transport properties of the high-entropy BaZr1/8Hf1/8Sn1/8Ti1/8Y1/8In1/8Sm1/8Yb1/8O3–x perovskite oxide with special focus on proton transport. The presented study is part of broader work in which we focus on multiple different chemical compositions with the cation number varying from 5 up to 12 (in B-sublattice). The presence of proton defects is analyzed with thermogravimetry,...
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The reactions of dialkyl phosphites and phosphine oxides with iodosylbenzene
PublicationThe reaction of iodosylbenzene with >P(O)H type of acids (dialkyl phosphites, secondary phosphine oxides) was studied. The acids of >P(O)H type add to iodosylbenzene to yield intermediate 6 which in the aprotic solvents yields oxidation products, it means >P(O)OH acids and/or anhydride of >P(O)OP(O)< type. On the other hand if the reaction is performed in alcohol as a solvent in the presence of sodium alcoholate >P(O)OR ester is...
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What is in a name: Defining “high entropy” oxides
PublicationABSTRACT High entropy oxides are emerging as an exciting new avenue to design highly tailored functional behaviors that have no traditional counterparts. Study and application of these materials are bringing together scientists and engineers from physics, chemistry, and materials science. The diversity of each of these disciplines comes with perspectives and jargon that may be confusing to those outside of the individual fields,...
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Synthesis, dispersion, and cytocompatibility of graphene oxide and reduced graphene oxide
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Thermodynamics of solid phases containing rare earth oxides
PublicationRare earth elements (RE) are incorporated into a large variety of complex oxide phases to provide tailored mechanical, electrical, optical, and magnetic properties. Thermodynamics control phase stability, materials compatibility in use, corrosion, and transformation. This review presents, in one compilation, the thermodynamic properties of a large number of such materials and discusses systematic trends in energetics and the factors...
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Proton conductivity in multi-component ABO4-type oxides
PublicationThis work investigates how configurational entropy in oxides could affect proton conductivity. For this purpose, three samples of different elemental compositions are synthesized. Five, six and seven elements were introduced into the A-site of ANbO4, forming La1/5 Nd1/5 Sm1/5Gd1/5 Eu1/5NbO4, La1/6Nd1/6Sm1/6Gd1/6Eu1/6Ho1/6NbO4 and La1/7Nd1/7Sm1/7Gd1/7Eu1/7Ho1/7Er1/7NbO4, respectively. The high configuration disorder changes the...
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Effect of iron oxides scaling on the MD process performance
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Ring Opening of Triflates Derived from Benzophospholan-3-one Oxides by Aryl Grignard Reagents as a Route to 2‑Ethynylphenyl(diaryl)phosphine Oxides
PublicationA new simple method for the synthesis of 2-ethynylphenyl(diaryl)phosphine oxides via ring opening of benzophosphol-3-yl triflates has been developed. This process occurs via nucleophilic attack of a Grignard reagent at the phosphorus center, which results in ring opening and cleavage of a leaving group. The reaction proceeds under mild conditions and, within 15−60 min, leads to a library of previously unavailable 2-ethynylphenylphosphine...
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Transition Metal Oxides influence on phosphate and borate glasses structure
PublicationBorate and phosphate glasses possess many potential luminescence and optical applications. With their low melting point, they are one of the most often studied amorphous materials. In recent years these glasses, doped with transition metal oxides (TMO), gained much attention due to their tunable structural and thermal properties. Review of systems containing TMOs was presented. Additionally synthesis of binary MnO-P2O5 and MnO-B2O3...
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Influence of hydrophobization of fumed oxides on interactions with polar and nonpolar adsorbates
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Positron Annihilation Studies of Silicon Oxides and Oxygen Precipitates in Silicon
PublicationTechniki pozytonowe dają możliwości badania defektów i zmian strukturalnych nie obserwowanych innymi metodami. W tej pracy zastosowano 3 różne techniki pozytonowe do badania zmian strukturalnych i tworzenia wydzieleń SiOx w krzemie.
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Benzophosphol-3-yl Triflates as Precursors of 1,3-Diarylbenzophosphole Oxides
PublicationAsimplemethodforthesynthesisof3-arylbenzophospholeoxidesunderSuzuki−Miyauracouplingconditionshasbeenpresented.Itemploysbenzophosphol-3-yltriflatestartingmaterialswhich,priortoourwork,hadnotbeenusedforthesynthesisof3-arylbenzophospholeoxides.Thereactionsproceedover24handprovidealibraryof3-arylbenzophospholeoxides.Thesyntheticaccesstothebenzophosphol-3-yltriflateshasbeenimproved.Thepreliminaryphotophysicalpropertiesofsome3-arylbenzophospholeoxideshavebeeninvestigatedbyabsorptionandemissionmeasurements.Thetheoreticalcalculationswereperformedtoestablishstructure−propertyrelationships.
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Novel Class of Proton Conducting Materials—High Entropy Oxides
PublicationHere, for the first time, we present data on proton conductivity of high-entropy, single-phase perovskites. The BaZr0.2Sn0.2Ti0.2Hf0.2Ce0.2O3−δ, BaZr0.2Sn0.2Ti0.2Hf0.2Y0.2O3−δ, BaZr1/7Sn1/7Ti1/7Hf1/7Ce1/7Nb1/7Y1/7O3−δ, and BaZr0.15Sn0.15Ti0.15Hf0.15Ce0.15Nb0.15Y0.10O3−δ single-phase perovskites were synthesized. Before electrical measurements, materials were characterized using X-ray diffraction (XRD), scanning electron microscopy...
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On the distribution of aluminium and magnesium oxides in wustite catalysts for ammonia synthesis
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Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties
PublicationA graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)- reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. In order to obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at constant potential of −0.85 V. The GO, RGO...
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Graphene oxide, reduced graphene oxide and composite thin films NO2 sensing properties
PublicationA graphene oxide (GO), reduced graphene oxide (RGO) and poly(3,4-ethylenedioxytiophene)-reduced graphene oxide (PEDOT-RGO composite) gas sensors were successfully fabricated using an electrodeposition method. The electrodeposition was carried out in aqueous GO dispersions. To obtain RGO and PEDOT-RGO, the electrochemical reduction of GO and PEDOT-GO was carried out in 0.1 M KCl at a constant potential of −0.85 V. The GO, RGO and PEDOT-RGO...
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Graphitic carbon nitride/graphene oxide/reduced graphene oxide nanocomposites for photoluminescence and photocatalysis
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Conductivity, structure, and thermodynamics of Y2Ti2O7–Y3NbO7 solid solutions
PublicationThe 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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Mobility measurements in oxide semiconductors
PublicationPraca zawiera wyniki badań właściwości elektrycznych, optycznych i strukturalnych cienkich warstw ito i sno2. badania wykazały, że cienkie warstwy tlenków metali wykazują rezystywność charakterystyczną dla półprzewodników. poziom transmisji światła w zakresie widzialnym pozwala zaliczyć badane warstwy do materiałów przezroczystych. badane cienkie warstwy wykonano metodą rozpylania magnetronowego.
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Evaluation of BaY1−Pr Mn2O5+δ oxides for oxygen storage technology
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Metal Oxides and Low Temperature SWCNT Synthesis via Laser Evaporation
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Properties of nanocrystalline TiO2:V thin films as a transparent semiconducting oxides
Publicationw pracy zaprezentowano wyniki badań cienkich warstw tlenku tytanu domieszkowanego wanadem. badany materiał charakteryzowano pod kątem wykorzystania, jako przezroczysty tlenek półprzewodnikowy (tos). warstwy zostały naniesione metodą rozpylania magnetronowego na szklane podłoża.
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Structural and Transportation Properties of Strontium Titanate Composites with Ion Conductive Oxides
PublicationThis 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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Water uptake and energetics of the formation of barium zirconate based multicomponent oxides
PublicationA 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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Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis
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A review of rare earth oxides-based photocatalysts: Design strategies and mechanisms
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Reduced Graphene Oxide Joins Graphene Oxide To Teach Undergraduate Students Core Chemistry and Nanotechnology Concepts
PublicationNovel carbon nanomaterials such as reduced graphene oxide (rGO) and graphene oxide (GO) can be easily incorporated into the undergraduate curriculum to discuss basic chemistry and nanotechnology concepts. This paper describes a laboratory experiment designed to study the differences between GO and rGO regarding their physico-chemical properties (e.g. color, hydrophobicity, type of functional groups, electrical conductivity etc.)....
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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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Electron attachment to hexafluoropropylene oxide (HFPO)
PublicationWe probe the electron attachment in hexafluoropropylene oxide (HFPO), C3F6O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10−4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20–100 mbar. In the latter method, the cross sections...
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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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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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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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Evaluation of Ln2CuO4 (Ln: La, Pr, Nd) oxides as cathode materials for IT-SOFCs
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Effective one-band Hamiltonian for the copper-oxygen plane in the superconducting copper oxides
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INFLUENCE OF THE MARINE 4-STROKE DIESEL ENGINE MALFUNCTIONS ON THE NITRIC OXIDES EMISSION
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Structure and transport properties of triple-conducting BaxSr1−xTi1−yFeyO3−δ oxides
PublicationIn this work, BaxSr1−xTi1−yFeyO3−δ perovskite-based mixed conducting ceramics (for x = 0, 0.2, 0.5 and y = 0.1, 0.8) were synthesized and studied. The structural analysis based on the X-ray diffraction results showed significant changes in the unit cell volume and Fe(Ti)–O distance as a function of Ba content. The morphology of the synthesized samples studied by means of scanning electron microscopy has shown different microstructures...
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Evaluation of La 2 Ni 0.5 Cu 0.5 O 4+δ and Pr 2 Ni 0.5 Cu 0.5 O 4+δ Ruddlesden-Popper-type layered oxides as cathode materials for solid oxide fuel cells
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