Electrical conductivity measurements for metals under shock compression

A novel method using four electrodes perpendicular to shock front was proposed to measure the electrical conductivity of metals under shock compression up to megabar pressures. Using the drilled sapphire disk as insulator can eliminate the shunting effect, which will result in a higher conductivity data. The electrical conductivities of iron under shock compression in the final equilibrium pressures ranging from 101 to 208 GPa were obtained by using the two-stage light gas gun techniques. The measured conductivity of iron varies from 1.45×106 S/m at 101 GPa and 2010 K, to 7.65×105 S/m at 208 GPa and 5220 K, which first extend the electrical conductivity measurements of iron to pressures beyond 200 GPa. The experimental results indicate that the Bloch-Gruneisen equation describing the high-pressure electrical conductivity of metals still holds true up to 200 GPa for Ε-Fe (hcp structure).