High field performance of PbMo6S8superconductors

Critical currents in Chevrel-phase lead molybdenum sulphide have been measured at two temperatures as a function of applied magnetic field up to 30 T. Improved critical current densities J
c
's were achieved with electroplating and diffusion processed PbMo
6
S
8
short-tapes. Increased J
c
values were obtained for a short heat-treatment at 1050 °C. We find a J
c
of
\sim 5\times10^{3}
A/cm
²
at 20 T and 4.2 K, and
\sim1\times10^{4}
A/cm
²
at 20 T and 1.6 K. The dependence of J
c
on grain size was also measured, and the correlation between flux pinning force and average grain size is discussed. The critical current density in the field range of < 27 T was strongly dependent on the grain size, and the critical currents at 14 T and 4.2 K can be scaled by the inverse grain size.