Formation of a new dynamical mode in -uranium observed by inelastic x-ray and neutron scattering.
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.
Manley
M E
ME
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Yethiraj
M
M
Sinn
H
H
Volz
H M
HM
Alatas
A
A
Lashley
J C
JC
Hults
W L
WL
Lander
G H
GH
Smith
J L
JL