Transport current density of (Bi1.6Pb0.4)Sr2Ca2Cu3O10 superconductor added with different nano-sized ZnO

The (Bi_1.6Pb_0.4)Sr₂Ca₂Cu₃O₁₀ZnO _x (x=0–0.05 wt%) superconductor with addition of ZnO with average particle size 6 nm and 30 nm was prepared using the co-precipitation method. The ZnO particle size was larger than the coherence length, ξ, and smaller than the penetration depth, λ, of the superconductor. The microstructure, transition temperature (T _c) and transport critical current density (J _c) were studied. SEM micrographs showed a homogeneous distribution of ZnO nanoparticles throughout the samples. J _c of all the ZnO added samples were higher than the non-ZnO added sample. The maximal J _c and T _c were observed when x=0.02 wt% for both series. J _c (77 K) of the 6-nm ZnO added sample was 46 times larger than the non-ZnO added sample. The 6-nm ZnO added sample also showed higher J _c compared to the 30-nm ZnO added sample. ZnO with size closer to ξ was more effective in enhancing J _c.