MgB2 tapes with 5 at.% Bi addition were fabricated through the in situ powder-in-tube method. Heat treatment was carried out at 700°C and 800°C for 1 h. The phase, microstructure, superconductivity and flux pinning ability were characterized by XRD, SEM, magnetic and transport measurements. The critical current density Jc and Jc-B performance for the doped and undoped samples are also given. It is found that nano-Bi doping decreased the magnetic field sensitivity of Jc, indicating an improvement of flux pinning. At 4.2 K, 10 T, Jc values of the Bi doped tapes enhanced about 2.5 times compared to that of undoped samples. The mechanism for improved Jc-B performance of Bi-doped MgB2 tapes is investigated.
- Critical current property
- Doping effect