HIGH FIELD PERFORMANCE OF PBMO₆S₈ SUPERCONDUCTORS.

Critical currents in chevrel-phase lead molybdenum sulfide have been measured at two temperatures as a function of applied magnetic field up to 30 T. Improved critical current densities J//c were achieved with electroplating and diffusion-processed PbMo//6S//8 short tapes. Increased J//c values were obtained for a short heat-treatment at 1050 degree C. Values of 5 multiplied by 10**3 A/cm**2 at 20 T and 4. 2 K and of 1 multiplied by 10**4 A/cm**2 at 20 T and 1. 6 K were found. The dependence of J//c on grain size was also measured, and the observed correlation between flux pinning force and average grain size is dicussed. The critical current density at fields less than 27 T was strongly dependent on the inverse of the average grain size.