Search results for "Quasielastic scattering"

showing 3 items of 33 documents

Studies of structure and dynamics of solid polymers by elastic and inelastic neutron scattering

1978

Abstract Neutron scattering methods can be applied to solid polymers in order to investigate the structure of the bulk material as well as the nature of the molecular motion. A review of some recently performed studies is presented. Diffusional motion in crystals of chain molecules has been studied by means of quasielastic scattering for the case of n-C33H68 as an example for the relationship between structure and molecular motion. It can be shown that below the so-called rotational transition the paraffin crystals exhibit two types of molecular motion: a translational jump (τt = 0.5 10-8s) and a 180°-rotational jump (τr = 2.5 10-8s). The low frequency vibrations in n-alkanes as models of p…

Quasielastic scatteringScatteringChemistryGeneral Chemical EngineeringDynamic structure factorQuasielastic neutron scatteringGeneral ChemistryInelastic scatteringAtomic physicsBiological small-angle scatteringNeutron scatteringSmall-angle neutron scatteringMolecular physicsPure and Applied Chemistry
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Inelastic neutron scattering measurements on Nd2Fe14B and Y2Fe14B single crystals

1992

Abstract Inelastic neutron scattering measurements have been carried out on Nd 2 Fe 14 B and Y 2 Fe 14 B single crystals. Temperature dependent acoustic magnon dispersion curves have been found along the high-symmetry directions [0,0,1] and [1,0,0] with a gap at (0,0,2). Soft mode behaviour at spin wave vector q = 0 was observed for Nd 2 Fe 14 B near the spin reorientation temperature. The inelastic scattering intensity decreases steeply for larger q . Therefore, the dispersion curves could be measured until the middle of the Brillouin zone only. The experimental results are discussed in the frame of a classical spin wave model.

Resonant inelastic X-ray scatteringPhysicsQuasielastic scatteringCondensed matter physicsMagnonDynamic structure factorQuasielastic neutron scatteringInelastic scatteringCondensed Matter PhysicsSmall-angle neutron scatteringInelastic neutron scatteringElectronic Optical and Magnetic MaterialsJournal of Magnetism and Magnetic Materials
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STUDIES OF STRUCTURE AND DYNAMICS OF SOLID POLYMERS BY ELASTIC AND INELASTIC NEUTRON SCATTERING

1979

Neutron scattering methods can be applied to solid polymers in order to investigate the structure of the bulk material as well as the nature of the molecular motion. A review of some recently performed studies is presented. Diffusional motion in crystals of chain molecules has been studied by means of quasielastic scattering for the case of n-C33H68 as an example for the relationship between structure and molecular motion. It can be shown that below the so-called rotational transition the paraffin crystals exhibit two types of molecular motion: a translational jump (τt = 0.5 10-8s) and a 180°-rotational jump (τr = 2.5 10-8s). The low frequency vibrations in n-alkanes as models of polyethyle…

chemistry.chemical_classificationQuasielastic scatteringMaterials scienceScatteringIncoherent scatterRotational transitionPolymerNeutron scatteringMolecular physicsInelastic neutron scatteringlaw.inventionchemistrylawCrystallization
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