Portal de Periódicos da CAPES

The effect of ZrSi 2 and SiC doping on the microstructure and J c – B properties of PIT processed MgB 2 tapes

2005; IOP Publishing; Volume: 19; Issue: 1 Linguagem: Inglês

10.1088/0953-2048/19/1/022

1361-6668

Yanwei Ma, Xianping Zhang, Aixia Xu, Xiaohang Li, Li-Ye Xiao, G. Nishijima, Satoshi Awaji, K. Watanabe, Y.L. Jiao, Ling Xiao, Xuedong Bai, Kehui Wu, Hai‐Hu Wen,

Iron-based superconductors research

We investigated the effect of ZrSi2 and SiC doping on the microstructure, critical current density Jc and flux pinning of Fe-sheathed MgB2 tapes prepared by the in situ powder-in-tube method. Heat treatment was performed at a low temperature of 650 °C for 1 h. The phases, microstructures and flux pinning were characterized by means of x-ray diffraction, scanning electron microscope, magnetic and transport property measurements. It was found that the tapes doped with nanoscale SiC had the best pinning performance, while the ZrSi2 powder showed a similar improved field dependence of Jc compared with undoped samples. Jc values for the SiC doped samples were enhanced by two orders of magnitude at 4.2 K in magnetic fields above 8 T. At 4.2 K and 10 T, the Jc reached ~1.5 × 104 A cm−2. Moreover, the critical temperature for the doped tapes decreased slightly (<1.2 K). Microstructural analysis shows that very good grain connections or/and grain refinement were obtained for the doped tapes. The mechanism of the enhancement of the flux pinning is also discussed.