Search results for "dopants"

showing 4 items of 4 documents

Ab initio calculations of pure and Co+2-doped MgF2 crystals

2020

This research was partly supported by the Kazakhstan Science Project № AP05134367«Synthesis of nanocrystals in track templates of SiO2/Si for sensory, nano- and optoelectronic applications», as well as by Latvian Research Council project lzp-2018/1-0214. Calculations were performed on Super Cluster (LASC) in the Institute of Solid State Physics (ISSP) of the University of Latvia. Authors are indebted to S. Piskunov for stimulating discussions.

AB INITIO CALCULATIONSNuclear and High Energy PhysicsMaterials scienceSpin statesBand gapAb initioENERGY GAP02 engineering and technologyFLUORINE COMPOUNDS01 natural sciences7. Clean energyMolecular physicsAb initio quantum chemistry methodsCobalt dopant0103 physical sciencesPhysics::Atomic and Molecular Clusters:NATURAL SCIENCES:Physics [Research Subject Categories]MgF2010306 general physicsFluorideInstrumentationCOBALT DOPANTSDopantCRYSTAL ATOMIC STRUCTUREDopingCOBALT COMPOUNDSMAGNESIUM COMPOUNDSDOPANT ENERGY LEVELS021001 nanoscience & nanotechnologyVIBRATIONAL STRUCTURESCALCULATIONSCRYSTALSGROUND STATELinear combination of atomic orbitalsCELL PROLIFERATIONAb initioGROUND STATE LEVELS0210 nano-technologyGround state
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Screening the bulk properties and reducibility of Fe-doped Mn2O3 from first principles calculations

2017

Abstract Manganese oxides, particularly Mn 2 O 3 , have demonstrated great potential for oxygen carrier materials in chemical looping applications. The application of these materials in the industrial scale is hindered by thermodynamic restrictions related to the reoxidation process. This disadvantage can be overcome by doping the oxide with a guest cation. Iron is one of the most promising dopants, but the atomic-level understanding of its effects on the properties of α-Mn 2 O 3 is incomplete. Herein, we report a systematic GGA+U study of the bulk properties and reducibility of Fe x Mn 2-x O 3 (0 ≤ x ≤ 2) as a function of Fe dopant concentration. In particular, we focus on a representative…

Band gapOxidechemistry.chemical_elementNanotechnology02 engineering and technologyManganeseBulk010402 general chemistry01 natural sciencesOxygenCatalysisCatalysischemistry.chemical_compoundta116density functional theoryFe dopantsDopantta114ChemistrytiheysfunktionaaliteoriaDopingOxygen transportGeneral Chemistry021001 nanoscience & nanotechnology0104 chemical sciencesMn2O3Physical chemistry0210 nano-technologyCatalysis Today
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Local structural investigation of hafnia-zirconia polymorphs in powders and thin films by X-ray absorption spectroscopy

2019

Björn Matthey (Fraunhofer IKTS, Dresden) is acknowledged for providing HfO2 and ZrO2 powders on short notice after DESY’s renowned customs office punished us. Parts of this research were carried out at Petra III at DESY, a member of the Helmholtz Association (HGF). The experiments on single Si:HfO2 thin film samples were performed at the CLAESS beamline at ALBA Synchrotron with the collaboration of ALBA staff. We would like to thank Edmund Welter for assistance (in using beamline P65) and DESY for enabling this research for proposal no. 20160591 and for travel support. T.S. acknowledges the German Research Foundation (DFG) for funding this work in the frame of the project “Inferox” (project…

Ferroelectrics670Materials sciencePolymers and PlasticsAbsorption spectroscopyexafsExtended X-ray absorption fine structure X-ray absorption near edge structure Ferroelectrics Hafnium oxide Zirconium oxide02 engineering and technologydopants01 natural sciencesferroelectric propertieshafnium oxideTetragonal crystal systemformer soviet-unionzirconium oxideddc:6700103 physical sciences:NATURAL SCIENCES:Physics [Research Subject Categories]Zirconium oxideX-ray absorption near edge structureThin filmx-ray absorption near edge structureExtended X-ray absorption fine structureHafnium oxideErweiterte Röntgenabsorptionsfeinstruktur Röntgenabsorptionsstruktur in Randnähe Ferroelektrika Hafniumoxid Zirkoniumoxid010302 applied physicsX-ray absorption spectroscopybiologyExtended X-ray absorption fine structureferroelectricsMetals and Alloyshfo2021001 nanoscience & nanotechnologyHafniabiology.organism_classificationXANESstabilizationdielectricsElectronic Optical and Magnetic Materialsoxygen-ion conductorselectrochemistryextended x-ray absorption fine structureChemical physicsCeramics and Compositesinterface0210 nano-technologyMonoclinic crystal systemActa Materialia
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Dopant radial inhomogeneity in Mg-doped GaN nanowires

2018

International audience; Using atom probe tomography, it is demonstrated that Mg doping of GaN nanowires grown by Molecular Beam Epitaxy results in a marked radial inhomogeneity, namely a higher Mg content in the periphery of the nanowires. This spatial inhomogeneity is attributed to a preferential incorporation of Mg through the m-plane sidewalls of nanowires and is related to the formation of a Mg-rich surface which is stabilized by hydrogen. This is further supported by Raman spectroscopy experiments which give evidence of Mg-H complexes in the doped nanowires. A Mg doping mechanism such as this, specific to nanowires, may lead to higher levels of Mg doping than in layers, boosting the po…

Materials scienceHydrogenNanowirechemistry.chemical_elementBioengineering02 engineering and technologyAtom probe01 natural scienceslaw.inventionsymbols.namesakelaw0103 physical sciencesGeneral Materials ScienceElectrical and Electronic Engineeringgallium nitride nanowires010302 applied physics[PHYS]Physics [physics]Dopantbusiness.industryMechanical EngineeringDopingGeneral Chemistryspatialinhomogeneity of dopants021001 nanoscience & nanotechnologymagnesium incorporationchemistryatom probe tomographyMechanics of MaterialsRaman spectroscopysymbolsOptoelectronics0210 nano-technologyRaman spectroscopybusinessMolecular beam epitaxyLight-emitting diode
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