High field properties of SnMo6S8and PbMo6S8ribbons prepared using a vapor transport technique

Superconducting ribbons of SnMo6S8and PbMo6S8have been produced using a one step vapor transport technique. In this process Sn or Pb vapor and H2S gas react at the surface of a Mo substrate at elevated temperatures to form a uniform coating of Chevrel phase. SEM micrographs show the film on the ribbons to be composed of small ( m) single-crystal rhombohedra of Chevrel phase. Critical currents for the SnMo6S8ribbons are similar to that achieved in PbMo6S8by other techniques ( A/cm²at 19 T and 4.2 K). The performance of our PbMo6S8is severely degraded. An explanation for this is based on larger intrinsic strain effects in the PbMo6S8.