Microstructure and Fluctuation-Induced Conductivity Analysis of Bi2Sr2CaCu2O8δ (Bi-2212) Nanowire Fabrics+

Crystals

卷:10

Yassine Slimani¹  XianLin Zeng²  Anjela Koblischka-Veneva²  MichaelRudolf Koblischka²  Essia Hannachi³ 

[1] Department of Biophysics, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia;

[2] Experimental Physics, Saarland University, P.O. Box 151150, D-66041 Saarbrücken, Germany;

[3] Laboratory of Physics of Materials—Structures and Properties, Department of Physics, Faculty of Sciences of Bizerte, University of Carthage, 7021 Zarzouna, Tunisia;

关键词: fluctuation-induced conductivity;    microstructure;    Bi-2212 superconductor;    nanofiber fabrics;    electrospinning;   

DOI  :  10.3390/cryst10110986

来源: DOAJ

【 摘 要 】

Resistance measurements were performed on Bi${}_2$Sr${}_2$CaCu${}_2$O${}_{8+\delta }$ (Bi-2212) fabric-like nanowire networks or nanofiber mats in the temperature interval 3 K $\le T\le$ 300 K. The nanowire fabrics were prepared by means of electrospinning, and consist of long (up to 100 $\mathsf{\mu }$m) individual nanowires with a mean diameter of 250 nm. The microstructure of the nanowire network fiber mats and of the individual nanowires was thoroughly characterized by electron microscopy showing that the nanowires can be as thin as a single Bi-2212 grain. The polycrystalline nanowires are found to have a texture in the direction of the original polymer nanowire. The overall structure of the nanofiber mats is characterized by numerous interconnects among the nanowires, which enable current flow across the whole sample. The fluctuation-induced conductivity (excess conductivity) above the superconducting transition temperature, $T_c$, was analyzed using the Aslamzov-Larkin model. Four distinct fluctuation regimes (short-wave, two-dimensional, three-dimensional and critical fluctuation regimes) could be identified in the Bi-2212 nanowire fabric samples. These regimes in such nanowire network samples are discussed in detail for the first time. Based on this analysis, we determine several superconducting parameters from the resistance data.

【 授权许可】

Unknown