Search

Dynamic equation-of-state data are presented for liquid ${\mathrm{N}}_{2}$ single- and double-shocked to pressures of 100 GPa (1 Mbar), compressions to fourfold over initial liquid density, and internal energies to 1 MJ/mole. Three double-shock points lie above the principal Hugoniot in pressure-volume space, the first such observation in condensed matter. The data are interpreted in terms of a continuous phase transition, identified as molecular dissociation by comparison of the shock compression curves of liquid ${\mathrm{N}}_{2}$ and isoelectronic CO.

New data are reported for liquid xenon shock compressed to a pressure of 130 GPa (1.3 Mbar), a molar volume of 13.7 ${\mathrm{cm}}^{3}$/mole, and a calculated temperature of 29 000 K. The data are consistent with the theory of Ross and McMahan, which indicates that xenon undergoes an insulator-to-metal transition at 9 ${\mathrm{cm}}^{3}$/mole at about 130 GPa or greater at 0 K. The minimum molar volume achieved in these experiments corresponds to a pressure of 60 GPa on the 0-K isotherm.