title: Formation of a new dynamical mode in -uranium observed by inelastic x-ray and neutron scattering.
abstract: Phonon dispersion curves were obtained from inelastic x-ray and neutron scattering measurements on alpha-uranium single crystals at temperatures from 298 to 573 K. Both measurements showed a softening and an abrupt loss of intensity in the longitudinal optic branch along [00zeta] above 450 K. Above the same temperature a new dynamical mode of comparable intensity emerges along the [01zeta] zone boundary with energy near the top of the phonon spectrum. The new mode forms without a structural transition but coincides with an anomaly in the mechanical deformation behavior. We argue that the mode is an intrinsically localized vibration and formed as a result of a strong electron-phonon interaction.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Manley
authors.forename: M
authors.initials: M
authors.lastname: Yethiraj
authors.forename: H
authors.initials: H
authors.lastname: Sinn
authors.forename: H M
authors.initials: HM
authors.lastname: Volz
authors.forename: A
authors.initials: A
authors.lastname: Alatas
authors.forename: J C
authors.initials: JC
authors.lastname: Lashley
authors.forename: W L
authors.initials: WL
authors.lastname: Hults
authors.forename: G H
authors.initials: GH
authors.lastname: Lander
authors.forename: J L
authors.initials: JL
authors.lastname: Smith