Enhancement of the low-field Jc properties of MgB2/Fe tapes by a modified in situ process
The low-field Jc properties of MgB2/Fe tapes were significantly improved by a modified in situ process. The as-drawn MgB2/Fe wires were first pre-annealed to form MgB2, before they were further rolled into flat tapes and post-annealed. In comparison to the conventional in situ process, our modified process produced dense, homogeneous and well-connected MgB2 cores in the final tapes, which resulted in a significant improvement in the low-field Jc properties. This modified in situ process is very promising for the fabrication of long-length MgB2 tapes/wires with excellent Jc properties for low-field applications, such as magnetic resonance imaging (MRI) magnets.