RESISTIVITY ANOMALIES AND SUPERCONDUCTIVITY IN NbS_3(LOCALIZATION AND SUPERCONDUCTIVITY IN ID CONDUCTORS, International Symposium on NONLINEAR TRANSPORT AND RELATED PHENOMENA IN INORGANIC QUASI ONE DIMENSIONAL CONDUCTORS)

Abstract

The dc and ac electrical conductivity measurements are reported on a quasi-one-dimensional conductor NbS_3. Sulfur-rich NbS-3 shows semiconducting property. Crystals are divided into two groups. One exhibits a resistivity anomaly around 140 K, and the other shows two successive resistivity anomalies around 235 and 140 K. Metallic NbS_3 was obtained by annealing the sulfur-rich or nearly stoichiometric crystals in a vacuum. In metallic NbS_3, existence of a superconducting phase transition below 2.15 K was observed on the basis of resistance and critical magnetic field measurements.