Search results for " Magnetic relaxation"

showing 4 items of 4 documents

Heuristic Algorithm for the Analysis of Fast Field Cycling (FFC) NMR Dispersion Curves

2021

Evaluation of nuclear magnetic relaxation dispersion (NMRD) curves obtained by the fast field cycling nuclear magnetic resonance (FFC-NMR) relaxometry technique is a valuable tool for analyzing the microscopic dynamics of condensed matter systems. However, quantitative data analysis involves several conceptual and practical issues. Moving forward from previous literature approaches, we propose a new analysis method, relying on the elaboration of the inverse integral transform of the NMRD curve. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains in the system, thereby avoiding the possible introduction of any element of discretion. The anal…

Nuclear magnetic relaxationNanospongesRelaxometryMagnetic Resonance SpectroscopyField cyclingHeuristic (computer science)Settore AGR/13 - Chimica AgrariaInverseHeuristic algorithm010402 general chemistry01 natural sciencesAnalytical ChemistryFFC NMRCheeseDispersion (optics)HeuristicsAnalysis methodSettore CHIM/02 - Chimica FisicaCyclodextrinsChemistry010401 analytical chemistrySettore CHIM/06 - Chimica OrganicaIntegral transformMagnetic Resonance Imaging0104 chemical sciencesRelaxometryAlgorithmAlgorithmsAnalytical Chemistry
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Dynamical Ising-like model for the two-step spin-crossover systems

2003

In order to reproduce the two-step relaxation observed experimentally in spin-crossover systems, we investigate analytically the static and the dynamic properties of a two-sublattice Ising-like Hamiltonian. The formalism is based on a stochastic master equation approach. It is solved in the mean-field approximation, and yields two coupled differential equations that correspond to the HS fractions of the sublattices A and B. Virginie.Niel@uv.es ; Jose.A.Real@uv.es

PhysicsDifferential equationsIsing model ; Magnetic transitions ; Magnetic relaxation ; Master equation ; Stochastic systems ; Differential equations ; Spin HamiltoniansMagnetic transitionsSpin HamiltoniansStochastic systemsDifferential equationTwo stepUNESCO::FÍSICAGeneral Physics and AstronomyCoupled differential equationssymbols.namesakeFormalism (philosophy of mathematics)Spin crossover:FÍSICA [UNESCO]Master equationIsing modelsymbolsIsing modelStatistical physicsMaster equationHamiltonian (quantum mechanics)Magnetic relaxation
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Single chain magnet behaviour in an enantiopure chiral cobalt(II)–copper(II) one-dimensional compound

2010

The self-assembly of an enantiomerically pure, chiral dianionic oxamatocopper(II) complex with cobalt(II) ions leads to neutral oxamato-bridged heterobimetallic chains that combine chirality and slow magnetic relaxation, providing thus the first example of ‘‘chiral single chain magnets (CSCMs). Ruiz Garcia, Rafael, Rafael.Ruiz@uv.es ; Lloret Pastor, Francisco, Francisco.Lloret@uv.es

StereochemistryHigh Energy Physics::LatticeUNESCO::QUÍMICAchemistry.chemical_elementSingle chainComputer Science::Computational Geometry010402 general chemistry01 natural sciences:QUÍMICA [UNESCO]CatalysisIonMagnetic RelaxationMaterials ChemistryMagnetic relaxation[CHIM.COOR]Chemical Sciences/Coordination chemistrySelf-assembly ; Dianionic oxamatocopper ; Cobalt ; Ions ; Magnetic RelaxationComputingMilieux_MISCELLANEOUSIons010405 organic chemistryUNESCO::QUÍMICA::Química inorgánicaHigh Energy Physics::PhenomenologyMetals and AlloysGeneral ChemistrySelf-assemblyCobalt:QUÍMICA::Química inorgánica [UNESCO]Copper3. Good health0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCrystallographyEnantiopure drugchemistryMagnetCeramics and CompositesDianionic oxamatocopperChirality (chemistry)Cobalt
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Time evolution of the microwave second-order response of YBaCuO powder

2003

Transient effects in the microwave second-order response of YBaCuO powder are investigated. The time evolution of the second harmonic signal has been measured for about 300 s after the sample had been exposed to variations of the DC magnetic field. We show that in different time scales the transient response has different origin. In the time scale of milliseconds the transient response of samples in the critical state is ascribable to processes of flux redistribution induced by the switching on/off of the microwave field. At longer times, the time evolution of the second harmonic signal can be ascribed to motion of fluxons induced by the variation of the DC magnetic field. In particular, di…

SuperconductivityMillisecondMaterials scienceCondensed matter physicsFluxonCondensed Matter - SuperconductivityTime evolutionEnergy Engineering and Power TechnologySecond-harmonic generationFOS: Physical sciencesCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsMagnetic fieldSuperconductivity (cond-mat.supr-con)Fluxon dynamics Magnetic relaxation Non-linear microwave responseTransient responseElectrical and Electronic EngineeringMicrowave
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