Size and proximity effects in multifilamentary superconducting wires

✍ Scribed by D.P. Lazar; N.M. Vladimirova; V.M. Drobin; E.I. Dyachkov; I.S. Khukhareva

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 393 KB
• Volume: 26
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(86)90213-4

✦ Synopsis

The longitudinal resistance of a copper matrix in commercial multifilamentary superconducting wires with various numbers and diameters of Nb-Ti filaments has been measured. This was done at a temperature, T ~ 12 K, when PNb-Ti ~ 10 3 PCu, SO that the longitudinal resistance of a sample is entirely determined by copper. For all samples the resistivity, Pll , in the core consisting of both Cu and Nb-Ti, is greater than the resistivity, Pcu, in the surface superconductor-free layer. Size effect makes a significant contribution to the value of Pll . If a current is passed through a multifilamentary superconducting wire perpendicular to the superconducting filaments, a state specific to two-dimensional superconductors is created. The temperature dependence of the transverse resistance of the samples used was analogous to that of the resistance of a twodimensional system. Thus, after the superconducting transition of the Nb-Ti-50 filaments, a decrease in the temperature leads to a monotonic decrease of the resistance due to the proximity effect. This is in good agreement with a mathematical model developed for such two-dimensional superconductors.