Effects of Zr, In and SiC Addition on the Critical Current in Filamentary MgB2 Superconductors by Suspension Spinning

Abstract

We have examined the effects of Zr, In and nanoscale SiC addition on the field dependence of transport Jc for filamentary MgB2 superconductors at 4.2 K in magnetic field up to 14 T. Suspension spinning of commercially available MgB2, and Zr, In or nanoscale SiC powders was used to fabricate a long superconducting MgB2 wire. The as‐drawn filaments were pressed and pyrolyzed to remove volatile components. The filamentary samples were then cold‐pressed, enveloped by an iron sheet with Mg powder or with a pellet of mixed powder of Mg and B, and vacuum‐sealed in a fused quartz tube and sintered. The Jc of the sample was strongly dependent on the sintering condition and addition content. 10 at% In addition enhanced the Jc at magnetic fields up to 8 T for the sample sintered with Mg powder. 5 at% SiC addition in the sample sintered with a pellet of Mg and B powders improved the Jc at fields of more than 7 T and the zero resistivity at 4.2 K was maintained by applying the field of 14 T. The magnetization for the ...