Measuring the temperature dependence of resistivity of high purity copper using a solenoid coil (SRPM method)

The resistivity of high-purity copper was measured by a method that estimates resistivity by using the difference in the impedance of a circular multilayer solenoid coil with a cylindrical copper core and an identical coil without a copper core (SRPM method). It was confirmed that an exact measurement of the resistivity of 10^-12 Ω-m can be made. The residual resistivity ratio (RRR) of high-purity copper measured at 100 Hz correlates well with the values measured by the DC four-probe method. The existence of frequency dependence was discovered at very low resistivity for high-purity copper. As the measuring frequency is raised, the skin depth seems to affect the surface resistivity due to the oxide coating and dirt on the surface of the samples