Enhancement of critical current densities by high-pressure sintering in (Sr,K)FeAs PIT wires

Pyon, S.*; Tsuchiya, Yuji*; Inoue, Hiroshi*; Kajitani, Hideki; Koizumi, Norikiyo; Awaji, Satoshi*; Watanabe, Kazuo*; Tamegai, Tsuyoshi*

Many scientists have been trying to improve the superconductor performance of ferrous strand "((Sr,K)FeAs" with improvement of the dope materials and fabricating process. Especially, it is expected that heat treatment under high pressure for the strand is good for improvement of the critical current performance because it makes intercrystalline bond power in the material stronger. In past study, using some kinds of tape strand, the improvement of critical current performance could be experimentally achieved with this method. In this paper, it is shown that the author newly fabricated rounded strand and HIP (700 degrees, 4 hours, 120 MPa) was applied for it and then the critical performance was measured. The result could be achieved as 1[kA/mm]. This high value is meaningful in terms of the application for the magnet and some apparatuses.