corner
corner

Phys. Rev. B 75, 104208 (2007) [9 pages]

Structure and dynamics of l-Ge: Neutron scattering experiments and ab initio molecular dynamics simulations

Download: PDF (816 kB) Buy this article Export: BibTeX or EndNote (RIS)

Virginie Hugouvieux*
Laboratoire des Colloïdes, Verres et Nanomatériaux, CNRS, UMR 5587, Université Montpellier 2, 34095 Montpellier Cedex 5, France and Institut Laue-Langevin, BP 156, 38042 Grenoble cedex 9, France

Emmanuel Farhi and Mark R. Johnson
Institut Laue-Langevin, BP 156, 38042 Grenoble cedex 9, France

Fanni Juranyi
Laboratory for Neutron Scattering, ETHZ and PSI, 5232 Villigen, Switzerland

Philippe Bourges
Laboratoire Léon Brillouin (CEA-CNRS), CEA Saclay, 91191 Gif-sur-Yvette cedex, France

Walter Kob
Laboratoire des Colloïdes, Verres et Nanomatériaux, CNRS, UMR 5587, Université Montpellier 2, 34095 Montpellier Cedex 5, France

Received 12 September 2006; revised 9 January 2007; published 28 March 2007

We report the first measurements of the dynamics of liquid germanium (l-Ge) by quasielastic neutron scattering on time-of-flight and triple-axis spectrometers. These results are compared with simulation data of the structure and dynamics of l-Ge which have been obtained with ab initio density functional theory methods. The simulations accurately reproduce previous results from elastic and inelastic scattering experiments, as well as the q dependence of the width of the quasielastic signal of the new experimental data. In order to understand some special features of the structure of the liquid we have also simulated amorphous Ge. Overall we find that the atomistic model represents accurately the average structure of real l-Ge as well as the time dependent structural fluctuations. The quasielastic neutron scattering data allows us to investigate to what extent simple theoretical models can be used to describe diffusion in l-Ge.

© 2007 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.75.104208
DOI:
10.1103/PhysRevB.75.104208
PACS:
61.25.−f, 61.12.Ex, 61.20.Ja

*Present address: Unité de Recherche Biopolymères, Interactions, Assemblages, INRA, BP 71627, 44316 Nantes cedex 3, France; Electronic address: virginie.hugouvieux@nantes.inra.fr