Raman spectroscopy of hot dense hydrogen.
High P-T Raman measurements of solid and fluid hydrogen to above 1100 K at 70 GPa and to above 650 K in 150 GPa range, conditions previously inaccessible by static compression experiments, provide new insight into the behavior of the material under extreme conditions. The data give a direct measure of the melting curve that extends previous optical investigations by up to a factor of 4 in pressure. The magnitude of the vibron frequency temperature derivative (dnu/dT)(P) increases by a factor of approximately 30 over the measured pressure range, indicating an increase in intrinsic anharmonicity and weakening of the molecular bond.
Gregoryanz
Eugene
E
Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road N.W., Washington, D.C. 20015, USA.
Goncharov
Alexander F
AF
Matsuishi
Kiyoto
K
Mao
Ho-kwang
HK
Hemley
Russell J
RJ