PROMISING CRITICAL-CURRENT DENSITY IN THE CHEVREL-PHASE SUPERCONDUCTING WIRES

Chevrel phase wires with high quality powder were made under very care ful conditions. Small coils of about 1 m wire length, treated under ho t isostatic pressing conditions, were measured in a magnetic field up to 15 T. We have obtained a critical current density of 5.0 x 10(8) A/ m(2) at 15 T and 4.2 K. This represents an improvement of 35% with res pect to the best reported results to date. We show that these J(c) val ues are still extrinsically limited by a few defects responsible for t he thermal quench of the coils. When it was possible to localise the d efects, holes in the anit-diffusion barrier were observed.