Role of the lattice in the gamma-->alpha phase transition of Ce: a high-pressure neutron and x-ray diffraction study.
The temperature and pressure dependence of the thermal displacements and lattice parameters were obtained across the gamma-->alpha phase transition of Ce using high-pressure, high-resolution neutron and synchrotron x-ray powder diffraction. The estimated vibrational entropy change per atom in the gamma-->alpha phase transition, DeltaS(gamma-alpha)(vib) approximately (0.75+/-0.15)k(B), is about half of the total entropy change. The bulk modulus follows a power-law pressure dependence that is well described using the framework of electron-phonon coupling. These results clearly demonstrate the importance of lattice vibrations, in addition to the spin and charge degrees of freedom, for a complete description of the gamma-->alpha phase transition in elemental Ce.
Jeong
I-K
IK
Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. jeong@lanl.gov
Darling
T W
TW
Graf
M J
MJ
Proffen
Th
T
Heffner
R H
RH
Lee
Yongjae
Y
Vogt
T
T
Jorgensen
J D
JD