CURRENT-CARRYING PROPERTIES OF THE HIP TREATED MO-SHEATH PBMO6S8 WIRES

Although the critical current density (Jc) over 2 x 10(8) A/m2 (8 T) is obtained for Mo-sheathed PbMo6S8 wires annealed at 700-degrees-C, the microstructure of PbMo6S8 is very porous and Jc measured with a magnetic field parallel to the current, Jc(parallel-to), is only 0-01% higher than Jc measured with a field perpendicular to the current, Jc(perpendicular-to). The transport current flows percolatively in PbMo6S8 of those wires. Remarkable Jc enhancement was observed for the wires HIP (hot isostatic pressing) treated at 1200-degrees-C: Jc > 3 x 10(8) A/m2 (8 T) has frequently been observed and the best value was Jc = 2.2 x 10(8) A/m2 (18 T) and 9.3 x 10(7) A/m2 (23 T). Moreover, a clear correlation was observed between the Jc(parallel-to)/Jc(perpendicular-to) ratios and the absolute Jc(perpendicular-to) values, which means that the observed Jc enhancement is due to the improved interconnectivity between PbMo6S8 grains. The prospect of the HIP treated Mo-sheath PbMo6S8 wires as a superconducting wire for extremely high field magnets is discussed.