Measuring material susceptibility using NMR

Abstract

We report on a method of measuring the high-field susceptibilities of paramagnetic and diamagnetic materials using only a standard NMR system equipped with pulsed field gradients. We demonstrate the accuracy and sensitivity of the technique by measuring a series of 99.9% copper wires with diameters between 0.16mm and 0.79mm. We measured the volumetric susceptibility of the copper to be χ=-9.5±0.2·10-6, which agrees with the literature value of pure copper, -9.6·10-6. In addition to making quantitative measurements, this technique can also be used to evaluate the effectiveness of compensation schemes used to produce “zero-susceptibility” materials needed for construction of high-resolution NMR probes.