Technique for high-pressure electrical conductivity measurement in diamond anvil cells at cryogenic temperatures

Abstract

A technique is described for making four‐probe electrical conductivity measurements on bulk samples in a diamond anvil cell. The technique has been successfully applied up to 48 GPa and at temperatures below 4.2 K to measure the superconducting transition temperatures (T_c, of Pb, GaP, and Si. A method for analyzing the resistance versus temperature curve in the vicinity of the superconducting transition is also described. This method is applied to determine the pressure dependence of T_c in Si in the region where T_c varies rapidly with pressure.