TRANSPORT CRITICAL CURRENT DENSITIES AND MAGNETIZATION IN SUPERCONDUCTING SILVER SHEATHED-AG, SN/YBCO COMPOSITE WIRES

Magnetic field dependence of transport critical current densities Jc(B) and dc magnetization M were measured for silver sheathed-YBCO superconducting wires added with various amounts of silver (Ag) and tin oxide (SnO2). Sample wires were fabricated by rolling and sintering at 910-degrees-C for 20h. The short sample wire has a length of 4 cm and core diameter of 1 mm, respectively. Zero field transport critical current densities Jc(O) with small amounts of SnO2 was more improved than that with Ag addition. For large amounts of Ag addition (10 approximately 40 wt%), the value of Jc(O) was reduced to half. Concerning the field dependence of Jc(B), small amounts of SnO2 addition was effective to increase the Jc(B) in the low field region (B < 10(-2) T) and intermediate field region (10(-2) T < B < 10(-1) T). In case of ternary system (Ag + Sn / YBCO), the value of Jc(B) seems to be mainly dominated by SnO2 content.