Jc increase of BPSCCO-2223 bulk by composing with Ag wires

To improve the superconducting properties of the high-T_c superconductors, we prepared the (Bi,Pb)₂Sr₂Ca₂Cu₃O_y (BPSCCO-2223) bulk composite with embedded Ag wires. The composites were hand-made by stacking alternately Ag wires into the oxide powder in the thickness direction, and then the prepared samples sintered at 840°C for 50 hours. SEM and EPMA observation showed that good c-axis oriented and densely structured BPSCCO-2223 plate-like grains could be formed around the interfacial region between BPSCCO-2223 oxide and metal Ag wire. We measured critical current density (J_c ) performance at 77.3 K and self-field and/or 4.2 K under several magnetic fields. As the J_c values of the BPSCCO-2223/Ag wires composite bulks were higher than that of BPSCCO-2223 bulk without Ag wires, J_c values were improved with increasing the number of Ag wires at several measurement conditions. The maximum J_c was obtained about 230 A/cm² at 77.3 K and self-field, 800 A/cm² at 4.2 K and self-field when forty-two Ag wires were composed. These J_c values corresponded to about twice that of BPSCCO-2223 oxide bulk without Ag wire. The improvement of J_c value was brought about by forming good c-axis oriented and densely structured BPSCCO-2223 plate-like grains