Textured Pb-Doped Bi-2212 Superconductors for Current Limiters

Bi2−xPbxSr2CaCu2Oy (x = 0.0, 0.3, 0.4, and 0.5) textured materials have been prepared by the laser floating zone technique. The E − I curves showed and increase of the slope of the normal to superconducting transition with Pb addition. The best values have been obtained for the 0.4 Pb-doped samples, around 16 at 77 K. In spite of this improvement, Pb addition decreased JC and TC in all cases. On the other hand, electrical characterization at lower temperatures has led to an impressive raise in the 0.4 Pb-doped samples, reaching n values around 31, and JC of about 3,000 A/cm 2, at 65 K. At the same time, the mechanical integrity of the vitreous precursor materials has been determined. All the obtained results clearly indicate that these precursors, when properly processed by the laser floating technique, are promising candidates for practical applications as current limiters.