Résumé
Phys. Rev. B 75, 104208 (2007) We report the first measurements of the dynamics of liquid germanium (l-Ge)
by quasi-elastic 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 quasi-elastic 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 new quasi-elastic neutron scattering data allows
us to investigate to what extent simple theoretical models can be used to
describe diffusion in l-Ge.