Pinning force scaling of electrospun Bi-2212 nanowire networks

Flux pinning forces were determined on different network samples of superconducting Bi₂Sr₂CaCu₂O₈ (Bi-2212) nanowires prepared by the electrospinning technique. We employed magnetization data determined by SQUID magnetometry in a wide temperature range 10 K <T< 35 K, where a strong superconducting signal prevails. The scaling analysis of the pinning forces was applied to interprete the data obtained. Both pure and Li-doped Bi2212 nanowire networks exhibit a peak position of h₀∼ 0.11, which is smaller than the expected value of h₀= 0.2 indicating flux pinning at grain boundaries or extended defects. For the flowing currents through such a network, the crystallographic anisotropy and the percolation play an important role, resulting in reduced peak positions as compared to bulk samples.