Determination of the precise upper critical field of YNi 2B 2C superconductor

Abstract

The paramagnetic susceptibility of YNi 2B 2C single crystal in a high magnetic field is found to be about 2×10 −5 cm 3/mol, which is one order of magnitude smaller than the previous reports. The paramagnetic behavior is caused by the sample impurity, not by the intrinsic magnetism of the YNi 2B 2C superconductor and shows simple Curie–Weiss behavior. In this case, an upper critical field of the YNi 2B 2C can be easily obtained by extracting the paramagnetic contribution. The upper critical field shows an anomalous behavior, the steep rising at the low temperature region.