Laser-Shocked Calcium Difluoride (Caf2) As A Warm Dense Matter

We determined the shock equation of state of CaF2 at pressures of similar to 0.4-1.5TPa using high-power laser shock techniques. The shock velocity-particle velocity was approximated by the universal Hugoniot relationship known to metallic fluids. Our results do not support the incompressible behavior above similar to 100GPa claimed previously. Warm dense CaF2 is a bonded liquid above the melting point and approaches an ideal fluid above similar to 1TPa. The measured reflectivity change of CaF2 at the shock front, similar to the other semiconducting liquids in the warm dense region, suggests a gradual metallization process due to the presence of delocalized electrons at high shock-front temperatures. Published under license by AIP Publishing.