Equation of state, adiabatic sound speed, and Grüneisen coefficient of boron carbide along the principal Hugoniot to 700 GPa

A equation of state (EOS) experimental technique that enables the study of thermodynamic derivatives into the TPa regime is described and applied to boron carbide (B4C). Data presented here are principal Hugoniot sound speed measurements reported using a laser-driven shock platform, providing a means to explore the high-pressure off-Hugoniot response of opaque materials. The extended B4C Hugoniot suggests the presence of a high-pressure phase, as recently predicted by molecular dynamics simulations, adding to the complexity of the existing phase diagram.