title: Cage diffusion in liquid mercury.
abstract: We present inelastic neutron scattering measurements on liquid mercury at room temperature for wave numbers q in the range 0.3 <q<7.0 A(-1). We find that the energy half width of the incoherent part of the dynamic structure factor S(q,E) is determined by a self-diffusion process. The half width of the coherent part of S(q,E) shows the characteristic behavior expected for a cage diffusion process. We also show that the response function at small wave numbers exhibits a quasielastic mode with a time scale characteristic of cage diffusion, however, its intensity is larger by an order of magnitude than what would be expected for cage diffusion. We speculate on a scenario in which the intensity of the cage diffusion mode at small wave numbers is amplified through a valence fluctuation mechanism.
authors.affiliation: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Yaspal S
authors.initials: YS
authors.lastname: Badyal
authors.forename: Ubaldo
authors.initials: U
authors.lastname: Bafile
authors.forename: Kunimasa
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Ignatz M
authors.initials: IM
authors.lastname: de Schepper
authors.forename: Wouter
authors.initials: W
authors.lastname: Montfrooij