An investigation was made of the effect of ZrSi2 and SiC doping on the microstructure, critical current density JC and flux pinning of Fe-sheathed MgB2 tapes prepared by using the in situ powder-in-tube method. Heat treatment was performed at 650C for 1h. The phases, microstructures and flux pinning were characterized by means of X-ray diffraction, scanning electron microscopic, magnetic and transport property measurements. It was found that the tapes doped with nanoscale SiC had the best pinning performance, while the ZrSi2 powder imparted a similar improved field dependence of JC as compared with undoped samples. The JC values of the SiC-doped samples were enhanced by 2 orders of magnitude at 4.2K in magnetic fields above 8T. At 4.2K and 10T, JC attained ~1.5 x 104A/cm2. Moreover, the critical temperature for the doped tapes decreased slightly (<1.2K). Microstructural analysis showed that very good grain connections or/and grain refinement were obtained for the doped tapes.

The Effect of ZrSi2 and SiC Doping on the Microstructure and JC–B Properties of PIT Processed MgB2 Tapes. Y.Ma, X.Zhang, A.Xu, X.Li, L.Xiao, G.Nishijima, S.Awaji, K.Watanabe, Y.Jiao, L.Xiao, X.Bai, K.Wu, H.Wen: Superconductor Science and Technology, 2006, 19, 133-7