Enhancement of transport J c in (Ba, K)Fe2As2 HIP processed round wires

Abstract

Iron-based superconductors have become a promising candidate for high-field applications due to their high transition temperature, ultra-high upper critical field, and low anisotropy. For practical applications, it is important to improve the transport J c and lower the cost of superconductors. In this paper, with groove rolling and hot isostatic pressing (HIP) process, the transport J c of the Cu/Ag composite sheathed (Ba, K)Fe2As2 powder-in-tube round wires was increased to 4.7 × 104 A cm−2 at 10 T and 4.2 K. The utilization of HIP and groove rolling process improved the mass density of the wire. Moreover, a certain axial texture was introduced through groove rolling. It is suggested that the combination of groove rolling and HIP processes are of great help to improve the microstructure of the wires, thereby obtaining a higher transport J c.