Processing and superconducting properties of the butt-joint of Bi-2212/Ag multifilamentary tape

Processing and the superconducting properties of the butt-joint for Bi-2212/Ag multifilamentary tapes were studied in relation to the crystal orientation. The multifilamentary Bi-2212/Ag tapes with 19 and 55 filaments were prepared by a powder-in-tube technique. The tapes were butt-jointed, followed by partially melting in a flowing oxygen atomosphere. The typical dimensions of the tapes used in the experiments were 5 mm in width, 0.15 mm in thickness, and 30 mm in length. The critical current I-c of the joint reached around 500 A, showing a great possibility for practical applications. The crystal alignment of the butt-jointed tape was analyzed by means of a transmissive X-ray diffraction method, and found the preferred orientation was realized in the joint part. The marked angular dependence of J(c) of the joint on angle between a tape and field at 4.2 K and 8-10 T also proved the c-axis alignment.