Spontaneous Raman Scattering from Shocked Water

Abstract

The OH-stretch Raman band of liquid water has been observed for the first time at high pressures and temperatures. A new single-pulse spontaneous Raman technique was used to obtain spectra from ${\mathrm{H}}_{2}$O shocked up to 26 GPa and 1700 K. Band-shape changes over the range 7.5-26 GPa are fitted well by a two-component mixture model. Intermolecular hydrogen bonding, dominant at 12 GPa, is nearly absent at 26 GPa. The spectra indicate that transport of ${\mathrm{H}}^{+}$ and O${\mathrm{H}}^{\ensuremath{-}}$ ions is most probably the mechanism for the electrical conductivity of shocked water.