Bi-2212/Ag tapes melt-grown under an elevated magnetic field (0–10 T)

Bi-2212/Ag tapes with a thickness of 30 μm were melt-grown in elevated magnetic fields following two different thermal sequences. The transport critical current density, J c dependence on the maximum processing temperature, cooling rate, holding time and magnetic field was studied systematically. The quantity of impurity phase was decreased by reducing the holding time above the melting point of Bi-2212 and optimizing the cooling rate in the partial-melt regime. Under these conditions, the overall degree of texture of the Bi-2212 tapes was increased. Application of a large magnetic field during melt-growth in the partial melt regime improved the amount of well textured Bi-2212 in the thick filaments, leading to increased critical current density J c. The highest J c (4.2 K, self field) obtained in this work was approximately 8.5×10 4 A/cm 2. It is demonstrated that a well textured structure and high J c can be achieved in thick Bi-2212 filaments.