Search results for "Structural transformation"

showing 6 items of 6 documents

A study of KNbO3in the pressure range to 12 GPa using synchrotron radiation

1997

Abstract Orthorhombic KNbO3 has been studied by x-ray diffraction as a function of pressure. The lattice cell parameters, volume and stability range of this phase have been determined as a function of the applied pressure. No structural transformation has been observed up to 12 GPa. The resulting P-V data are fitted to a Murnaghan equation state of first-order.

DiffractionMaterials sciencebusiness.industrySynchrotron radiationThermodynamicsCondensed Matter PhysicsStructural transformationElectronic Optical and Magnetic MaterialsPressure rangeCondensed Matter::Materials ScienceOpticsLattice (order)Orthorhombic crystal systembusinessFerroelectrics Letters Section
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Structure and superconducting properties of YBa2(Cu1−x Fex)3O7

1988

Fe-substituted Y-Ba-Cu superconducting oxide compounds were investigated by dc-magnetic susceptibility measurements, powder X-ray diffraction and Mdssbauer spectroscopy. Fe substitution caused a structural transformation from orthorhombic to tetragonal. Up to 4 at% Fe Tc was almost unaffected. It was found that superconductivity in Cu oxides does not depend on orthorhombic crystal symmetry.

DiffractionSuperconductivityMaterials scienceCondensed matter physicsOxideEnergy Engineering and Power TechnologyCondensed Matter PhysicsStructural transformationElectronic Optical and Magnetic MaterialsTetragonal crystal systemCrystallographychemistry.chemical_compoundchemistryOrthorhombic crystal systemElectrical and Electronic EngineeringSpectroscopyPhysica C: Superconductivity
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Structure evolution and reaction mechanism in the Ni/Al reactive multilayer nanofoils

2014

Abstract The extremely rapid gasless reactions in binary Ni/Al reactive multilayer nanofoils (RMNFs) are investigated both experimentally and theoretically. The quenching technique is used to study the dynamics of structural transformation on the micro- and nanoscales. The experimentally obtained patterns of structural evolution related to the heterogeneous reactions are compared with the results of molecular dynamics simulations carried out for the same reactive system. Based on the obtained data, the intrinsic mechanism of the reaction in Ni/Al RMNF is considered, which adequately explains the unusual parameters of a gasless combustion wave in such a system.

QuenchingReaction mechanismMaterials sciencePolymers and PlasticsMetals and AlloysCombustionStructural evolutionStructural transformationElectronic Optical and Magnetic MaterialsMolecular dynamicsComputational chemistryChemical physicsCeramics and CompositesReactive systemActa Materialia
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Solvent induced single-crystal to single-crystal structural transformation and concomitant transmetalation in a 3D cationic Zn(II)-framework.

2015

A 3D cationic Zn(II) framework, based on Zn2(CO2)4 paddle-wheel secondary building units (SBUs) and Zn16(CO2)32 polyhedral supramolecular building blocks (SBBs), has been synthesized. At room temperature, the framework undergoes guest solvent triggered reversible structural transformation and concomitant Zn(II) to Cu(II) transmetalation in a single-crystal to single-crystal fashion.

Chemistryconcomitant transmetalationMetals and AlloysCationic polymerizationSupramolecular chemistryGeneral Chemistrystructural transformationPhotochemistrysingle crystalsCatalysisStructural transformationSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsSolventTransmetalationPolymer chemistryMaterials ChemistryCeramics and CompositesSBusSingle crystalta116Chemical communications (Cambridge, England)
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Low temperature structural transformations on the (001) surface of SrTiO 3 single crystals

2020

This work was supported by the Ministry of Education and Science of Ukraine under the contract M/51–2019 within the framework of the Program of Ukrainian–Latvian Scientific and Technical Cooperation and Latvian–Ukranian Grant LV-UA/2018/2. Authors are indebted to L.L. Rusevich, G. Zvejnieks, V.P. Gnezdilov and A. Glamazda for stimulating discussions.

Phase transitionMaterials sciencePhysics and Astronomy (miscellaneous)General Physics and Astronomy01 natural sciences7. Clean energysymbols.namesakeTetragonal crystal systemchemistry.chemical_compound0103 physical sciences:NATURAL SCIENCES:Physics [Research Subject Categories]strontium titanate010306 general physics010302 applied physicssurface structural transformationsCondensed matter physicsAtmospheric temperature rangeFerroelectricityreflection high–energy electron diffraction (RHEED)Electron diffractionFerromagnetismchemistryRaman spectroscopysymbolsStrontium titanateRaman spectroscopyLow Temperature Physics
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Advancing the treatment of human agency in the analysis of regional economic development: Illustrated with three Norwegian cases

2021

Human agency has become a core topic in economic geography complementing traditional, structural approaches to explain regional development. This paper contributes firstly with a discussion of the theoretical and conceptual relationships between the agency of individuals, organizations, and systems. Secondly, it proposes a novel analytical framework for studying how human agency, combined with external changes affects regional economic development, and how regional structural preconditions and external changes explain the activation of change agency. Thirdly, the relevance of the framework is examined through comparative studies of about 20 years of industrial development in three Norwegian…

Global and Planetary ChangeEconomic growthVDP::Samfunnsvitenskap: 200::Økonomi: 210::Samfunnsøkonomi: 212Unintended consequencesAgency (philosophy)Context (language use)Human agencyNorwegianRegional developmentRegional policylanguage.human_languageVDP::Samfunnsvitenskap: 200::Økonomi: 210regional utviklingRegional developmentPolitical sciencelanguageRelevance (law)økonomisk geografiStructural transformationTransformation processes:Samfunnsvitenskap: 200::Økonomi: 210 [VDP]
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