Significant improvement in critical current densities of C-doped MgB 2 tapes made by high-energy ball milling Article

cited authors

  • Wang, C; Ma, Y; Zhang, X; Gao, Z; Wang, D; Yao, C; Wang, C; Oguro, H; Awaji, S; Watanabe, K

fiu authors

abstract

  • C-doped MgB 2 tapes were fabricated using crystalline boron as one of the ball milled precursor powders. It was found that the ball milling process can strongly enhance the J c values of MgB 2 tapes and reduce the anisotropy of the J c. At 4.2K, the transport J c of the 80h milled C-doped MgB 2 tapes sintered at 800°C reaches 4.3×10 4Acm 2 at 10T and 2.2×10 4Acm 2 at 12T, respectively. These values are even higher than for tapes made from amorphous B powders. Ball milling can improve not only the upper critical field, by increasing the C substitution level in the MgB 2 lattice, but also the flux pinning, by increasing grain boundaries, both of which result in the enhancement of J c performance. Moreover, the high MgB 2 phase fraction and large density of milled MgB 2 tapes are beneficial to the active area. These results indicate that the use of crystalline B in combination with a ball milling process may be an economic method to harness the excellent properties of MgB 2 for practical applications. © 2012 IOP Publishing Ltd.

publication date

  • July 1, 2012

Digital Object Identifier (DOI)

volume

  • 25

issue

  • 7