Optimization of critical currents on MgB2 wires and tapes

G.SERRANO; A.SERQUIS; L.CIVALE; B.MAIOROV; M.T.MALACHEVSKY; C.AYALA; G.BRIDOUX

Colorado. EE.UU.

Conferencia; International Cryogenic Materials Conference ICMC; 2005

The power-in-tube (PIT) method is one of the best procedures for processing of MgB2 superconducting wires and tapes. Previous results indicate that low level of doping with Al, C and nano SiC powders improves the critical current density (Jc) of MgB2 bulk samples. Besides, the relatively low values for the upper critical field (Bc2) reported for MgB2 in the early days were rapidly overcome by the enormous progress achieved in bulk samples and thin films in the so-called dirty limit. Therefore, the optimization of the fabrication process for MgB2 long conductors should also include methods to enhance Bc2 and the irreversibility field (B*). In this paper we report on the fabrication and characterization of doped MgB2 wires and tapes prepared by PIT with commercial stainless steel and Ti sheaths. A series of samples have been prepared by different mechanic deformation procedures and sintered at different temperatures between 500°C and 950°C, in order to correlate their superconducting properties such as Jc, Bc2 and B* with the fabrication conditions and the doping content.