Calculated phonon spectra of plutonium at high temperatures.
We constructed computer-based simulations of the lattice dynamical properties of plutonium using an electronic structure method, which incorporates correlation effects among the f-shell electrons and calculates phonon spectra at arbitrary wavelengths. Our predicted spectrum for the face-centered cubic delta phase agrees well with experiments in the elastic limit and explains unusually large shear anisotropy of this material. The spectrum of the body-centered cubic phase shows an instability at zero temperature over a broad region of the wave vectors, indicating that this phase is highly anharmonic and can be stabilized at high temperatures by its phonon entropy.
Department of Physics and Astronomy and Center for Materials Theory, Rutgers University, Piscataway, NJ08854, USA.
X
X
Dai
S Y
SY
Savrasov
G
G
Kotliar
A
A
Migliori
H
H
Ledbetter
E
E
Abrahams