Effect of nanoparticles with different size on the transport critical current density of Bi1.6Pb0.4Sr2Ca2Cu3O10 superconductor

Abstract

In general, for a nanoparticle to act as a pinning center, the size L should be larger than the coherence length, x and smaller than the penetration depth, λ. In this paper we compared the effects of different nano-sized particles (where x < L < λ), MgO (20 and 40 nm) versus ZnO (6 and 30 nm) on the transport critical current density of the Bi-based superconductors. All nanoparticle added samples showed higher transport critical current density, J c compared with the non-added samples. In Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3 O 10 (MgO) x , the 20 nm MgO added samples showed a higher J c compared with the 40 nm MgO added samples. The 6 nm ZnO added samples also showed higher J c compared to the 30 nm added samples. These results showed that the size of flux pinning center is important in enhancing J c and particle with size closer to the coherence length showed higher transport critical current density.