Raman scattering and x-ray diffraction experiments for phase III of solid hydrogen

Abstract

Raman scattering experiments were carried out at pressure up to 296 GPa at low temperature. The behaviors of spectral data were consistent with previous results. The frequency of the vibron, however, did not show linear pressure dependence, contrary to the previous report. Darkening of the hydrogen sample was observed above 270 GPa. The band gap closure of solid hydrogen is expected to be 400-450 GPa. Diffraction data of phase III were obtained with monitoring the transition into phase III by in situ measurement of Raman vibron frequencies of hydrogen. © 2010 IOP Publishing Ltd.