Pressure-enhanced ortho-para conversion in solid hydrogen up to 58 GPa.
We measured the ortho-para conversion rate in solid hydrogen by using Raman scattering in a diamond-anvil cell, extending previous measurements by a factor of 60 in pressure. We confirm previous experiments that suggested a decrease in the conversion rate above about 0.5 GPa. We observe a distinct minimum at 3 GPa followed by a drastic increase in the conversion rate to our maximum pressure of 58 GPa. This pressure enhancement of conversion is not predicted by previous theoretical treatments and must be due to a new conversion pathway.
Eggert
J H
JH
Department of Physics, Colorado School of Mines, Golden, CO 80401, USA.
Karmon
E
E
Hemley
R J
RJ
Mao
A
A
Goncharov
A F
AF