Evidence for superior current carrying capability of iron pnictide tapes under hydrostatic pressure



Publication Details

Shabbir, B., Huang, H., Yao, C., Ma, Y., Dou, S., Johansen, T., Hosono, H. & Wang, X. (2017). Evidence for superior current carrying capability of iron pnictide tapes under hydrostatic pressure. Physical Review Materials, 1 (4), 044805-1-044805-7.


High critical current density (Jc) values in superconducting wires/tapes are desirable for high magnetic field applications. Recently developed pnictide wires/tapes exhibit exceptional superconducting properties such as high critical temperature (Tc), upper critical field (Hc2), and almost field-independent Jc. Despite the great fabrication efforts, however, the newly discovered pnictide wires/tapes are still not able to replace low-temperature superconductors such as Nb3Sn, due to their inferior Jc values. Ag-clad Sr0.6K0.4Fe2As2 tapes have demonstrated significant superconducting performance, although their low Jc in comparison to Nb3Sn is still a major challenge. By successfully employing hydrostatic pressure, a remarkably significant enhancement of Jc by an order of magnitude can be achieved in Sr0.6K0.4Fe2As2 tapes in both low and high fields. This is a promising technological step forward towards high-field applications, as the record high Jc values (∼2x105A/cm2 at 4.2 K and 13 T, P=1.1GPa) obtained for Sr0.6K0.4Fe2As2 tape are superior to those of Nb3Sn and other pnictide wires/tapes. Here, we used magnetic Jc data for comparison to the other reported transport Jc data, due to the lack of transport measurement facility under hydrostatic pressure. Our systematic analysis shows that pressure-induced pinning centers are the main source of Jc enhancement, along with a fractional contribution from geometric changes around the grain boundaries under pressure. We expect that utilization of an appropriate pressure approach will be a way to significantly enhance Jc to beyond the cutoff (maximum) values in various superconductors produced using other existing methods for Jc enhancement.

Grant Number


Grant Number


Please refer to publisher version or contact your library.