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.
Mineral Physics Group, Box 351310, University of Washington, Seattle, Washington 98195, USA.
Subrata
S
Ghose
Michael
M
Krisch
Artem R
AR
Oganov
Alexandre
A
Beraud
Alexey
A
Bosak
Revansidha
R
Gulve
Raghunandan
R
Seelaboyina
Hexiong
H
Yang
Surendra K
SK
Saxena