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Arnold, René; Hefeker, Carsten; Luhmann, Hans‐Jochen; Dudenhöffer, Ferdinand

doi:10.1007/s10273-014-1747-x

Cited by 2 publications

(2 citation statements)

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“…Subsequently, the data were transformed from instrument coordinates, including the 2-theta and time of event, to the physical momentum transfer, Q, and energy transfer, E, using the MANTID reduction software. 34 For the powder sample, the scattering from the empty container was processed identically and subtracted from the sample measurements. The experimental phonon DOS was analyzed within the incoherent scattering approximation, and corrected for multi-phonon scattering effects.…”

Section: Experimental Methodsmentioning

confidence: 99%

Weak coupling of pseudoacoustic phonons and magnon dynamics in the incommensurate spin-ladder compound Sr14Cu24O41

et al. 2016

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Intriguing lattice dynamics has been predicted for aperiodic crystals that contain incommensurate substructures. Here we report inelastic neutron scattering measurements of phonon and magnon dispersions in Sr 14 Cu 24 O 41 , which contains incommensurate one-dimensional (1D) chain and two-dimensional (2D) ladder substructures. Two distinct acoustic phonon-like modes, corresponding to the sliding motion of one sublattice against the other, are observed for atomic motions polarized along the incommensurate axis. In the long wavelength limit, it is found that the sliding mode shows a remarkably small energy gap of 1.7-1.9 meV, indicating very weak interactions between the two incommensurate sublattices. The measurements also reveal a gapped and steep linear magnon dispersion of the ladder sublattice. The high group velocity of this magnon branch and weak coupling with acoustic phonons can explain the large magnon thermal conductivity in Sr 14 Cu 24 O 41 crystals. In addition, the magnon 2 specific heat is determined from the measured total specific heat and phonon density of states, and exhibits a Schottky anomaly due to gapped magnon modes of the spin chains.These findings offer new insights into the phonon and magnon dynamics and thermal transport properties of incommensurate magnetic crystals that contain low-dimensional substructures.

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Section: Experimental Methodsmentioning

confidence: 99%

Weak coupling of pseudoacoustic phonons and magnon dynamics in the incommensurate spin-ladder compound Sr14Cu24O41

et al. 2016

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“…The raw data obtained at HFBS, DCS, and NSE were reduced using the DAVE software package [76] and those at TOFTOF using Mantid [77].…”

Section: B Quasielastic Neutron Scatteringmentioning

confidence: 99%

Hydrogen diffusion in bulk and nanocrystalline palladium: A quasielastic neutron scattering study

et al. 2016

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The diffusion dynamics of hydrogen in bulk and nanocrystalline palladium has been examined using quasielastic neutron scattering (QENS). With respect to bulk PdH0.73, two relaxation processes were found. For both processes, the variation of the relaxation times with momentum transfer was well reproduced by a model of jump diffusion between adjacent octahedral sites. Upon cooling the fast relaxation fraction decreases. The result suggests that the slow relaxation corresponds to jumps between the ground states and the fast one between excited states. In nanocrystalline PdH0.47 with a size of 8 nm, we found a new fast diffusion process with a smaller activation energy in addition to the one observed in the bulk sample. The new process could be due to the motion of hydrogen atoms in the subsurface region where the potential energy surface is substantially modified by surface strain/distortion effects. This is the first QENS experiment that probes hydrogen diffusion within Pd nanoparticles.

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Concise comments

Cited by 2 publications

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Weak coupling of pseudoacoustic phonons and magnon dynamics in the incommensurate spin-ladder compound Sr14Cu24O41

Weak coupling of pseudoacoustic phonons and magnon dynamics in the incommensurate spin-ladder compound Sr14Cu24O41

Hydrogen diffusion in bulk and nanocrystalline palladium: A quasielastic neutron scattering study

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