Preparation and transport Jc(B) properties of Fe-clad MgB2 wires

Long dense MgB2 wires were successfully fabricated through the in situ powder-in-tube method by using steel sheath with low carbon content. Short samples of MgB2/Fe wires were sintered at 650-850 degreesC for 2-5 h in argon. Critical current density (J(c)) of the wires was measured in the temperature range of 4.2-30 K in the magnetic field up to 3 T by standard four probe method. High J(c) values of 1.3 x 10(5) A/cm(2) in self-field and 7.5 x 10(4) A/cm(2) in 1 T at 15 K were obtained for MgB2/Fe wires. The microstructure observation for MgB2 wires shows that no reaction between Fe and MgB2 was found and MgB2/Fe wires have better grain connectivity and higher density than MgB2 bulk samples. The grain connectivity in wires is better than MgB2 bulk samples. The results indicate that the Jc can be further improved to meet the requirement for applications by optimizing the process conditions. (C) 2002 Elsevier Science B.V. All rights reserved.