Lattice dynamics of MgO at high pressure: theory and experiment.
The longitudinal acoustic and optical phonon branches along the Gamma-X direction of MgO at 35 GPa have been determined by inelastic x-ray scattering using synchrotron radiation and a diamond-anvil cell. The experimentally observed phonon branches are in remarkable agreement with ab initio lattice dynamics results. The derived thermodynamic properties, such as the specific heat CV and the entropy S are in very good accord with values obtained from a thermodynamically assessed data set involving measured data on molar volume, heat capacity at constant pressure, bulk modulus and thermal expansion.
Ghose
Subrata
S
Mineral Physics Group, Box 351310, University of Washington, Seattle, Washington 98195, USA.
Krisch
Michael
M
Oganov
Artem R
AR
Beraud
Alexandre
A
Bosak
Alexey
A
Gulve
Revansidha
R
Seelaboyina
Raghunandan
R
Yang
Hexiong
H
Saxena
Surendra K
SK