Effect of nanometer MgO addition on the in situ PIT processed MgB2/Fe tapes

Nanometer MgO (nano-MgO) particles were introduced into MgB2 tapes prepared by the in situ PIT process to elucidate the influence of this major impurity phase in MgB2 tapes and wires on the current transport property. The critical temperature, microstructure, flux pinning ability and transport property of MgB2 tapes were studied with respect to the doping contents of nano-MgO particles. It was found that light doping of nano-MgO (⩽2.5 wt.%) could increase the Jc property of MgB2 tapes through enhancing the grain connectivity and core density. A 50% enhancement in Jc (10 T, 4.2 K) was obtained when adding 1.25 wt.% nano-MgO into MgB2. Further increasing the doing content of nano-MgO would decrease the critical temperature of MgB2 rapidly, however, the excess nano-MgO particles might be able to serve as extra pinning centers, which improved the Jc-B performance of MgB2 at higher temperature and in higher magnetic field.