Contactless method for magnetoresistivity measurements

A method is described to measure, at the liquid helium temperature, the resistivity and magnetoresisti vity of cylindrical metal bars by means of magnetization techniques used for superconductor ac loss measurements. The specimen is exposed to a variable ramp-like magnetic field in the axial direction. By means of two pick-up coils the magnetization hysteresis loop associated with eddy currents is recorded. Since the magnetization M of the bar is inversely proportional to resistivity ρ, the positive branch of the hysteresis loop also represents the dependance of 1/ρ on H. The results obtained for OFHC and 99.999% purity copper agree with those reported in the literature.