Abnormal electric conductivity of lithium at high dynamic pressure

New results obtained for lithium, quasi-isentropically compressed in multistep shock experiments up to pressure of 210 GPa and density of 2.3 g/cc, are reported. We studied the electric conductivity of dynamically compressed lithium. The pressure range to 100 GPa has been investigated at liquid nitrogen (77 K) and room (293 K) initial temperatures. In the second series of measurements used was the symmetrical scheme of compression with two high velocity impactors striking baseplates synchronically from opposite directions. It made it possible to achieve much higher pressures up to 2 10 GPa. The analysis of experimental data showed that lithium compressed to 210 GPa pressure demonstrates the abnormal dependence of electric resistivity. As against normal behavior of metal, the resistivity monotonically increases in the pressure range 30-150 GPa from typical metallic value at ambient conditions in more than 15 times, returning back to metallic one at pressure higher than 160-210 GPa. The results obtained agree with recent calculations of phase transitions in lithium at high pressure.