Superconducting Properties of Chevrel-Phase PbMo6S8 Wires by an Improved Powder Process

Abstract

A Chevrel-phase PbMo6S8 superconductor is one of the most promising superconducting wires for very high field magnets. In this study, PbMo6S8 superconducting wires fabricated by using a Ta barrier in a powder process have been heat-treated under high hydrostatic pressure for producing PbMo6S8 compound. And then superconductivity measurements and microstructure observations have been performed. The wires are very easily drawn to a final size at room temperature, and have a critical current density (Jc) for the compound of 1.7×104A/cm2 at 12T. The typical transition temperature (Tc) and its width, ΔTc are 14.5K and 0.6K, respectively. Furthermore, EPMA and PSPC-type X-ray Microdiffractometer observations indicate Mo, MoO2 precipitates and unreacted MoS2 in the compound core inside the Ta barrier. Consequently, the PbMo6S8 wires with excellent Jc at high fields can be fabricated by using a Ta barrier and heat-treating under hydrostatic pressure.