title: Computation of diffuse scattering arising from one-phonon excitations in a neutron time-of-flight single-crystal Laue diffraction experiment.
abstract: Direct phonon excitation in a neutron time-of-flight single-crystal Laue diffraction experiment has been observed in a single crystal of NaCl. At room temperature both phonon emission and excitation leave characteristic features in the diffuse scattering and these are well reproduced usingabinitiophonons from density functional theory (DFT). A measurement at 20 K illustrates the effect of thermal population of the phonons, leaving the features corresponding to phonon excitation and strongly suppressing the phonon annihilation. A recipe is given to compute these effects combining DFT results with the geometry of the neutron experiment.
authors: ISIS Facility, Rutherford Appleton Laboratory , Chilton, Didcot, Oxfordshire OX11 0QX, UK.
authors: Matthias J
authors: MJ
authors: Gutmann
authors: Thomas Young Centre, London Centre for Nanotechnology and Department of Chemistry, University College London , London WC1E 6BT, UK ; ISIS Facility, Rutherford Appleton Laboratory , Chilton, Didcot, Oxfordshire OX11 0QX, UK.
authors: Gabriella
authors: G
authors: Graziano
authors: ISIS Facility, Rutherford Appleton Laboratory , Chilton, Didcot, Oxfordshire OX11 0QX, UK.
authors: Sanghamitra
authors: S
authors: Mukhopadhyay
authors: ISIS Facility, Rutherford Appleton Laboratory , Chilton, Didcot, Oxfordshire OX11 0QX, UK ; Department of Physics, Royal Holloway , University of London, Egham TW20 0EX, UK.
authors: Keith
authors: K
authors: Refson
authors: Deutsches Elektronen Synchrotron DESY , Notkestrasse 85, Hamburg 22603, Germany.
authors: Martin
authors: M
authors: von Zimmerman
keywords: Laue diffraction; neutron time-of-flight; phonon excitation; single crystals