The onset of dissipation in high-temperature superconductors: magnetic hysteresis and field dependence

作     者：Talantsev, E. F. Strickland, N. M. Wimbush, S. C. Brooks, J. Pantoja, A. E. Badcock, R. A. Storey, J. G. Tallon, J. L. 

作者机构：Russian Acad Sci MN Mikheev Inst Met Phys Ural Branch 18 S Kovalevskoy St Ekaterinburg 620108 Russia Ural Fed Univ NANOTECH Ctr 19 Mira St Ekaterinburg 620002 Russia Victoria Univ Wellington Robinson Res Inst 69 Gracefield Rd Lower Hutt 5010 New Zealand Victoria Univ Wellington MacDiarmid Inst Adv Mat & Nanotechnol POB 600 Wellington 6140 New Zealand 

出 版 物：《SCIENTIFIC REPORTS》 (Sci. Rep.)

年 卷 期：2018年第8卷第1期

页      面：14463-14463页

核心收录：

基　　金：FASO of Russia [AAAA-A18-118020190104-3] Act 211 Government of the Russian Federation [02.A03.21.0006] 

主　　题：Current Transport Critical Current Electric Field Measurements Hall Sensor Array Sunami 

摘      要：Recently, we showed that the self-field transport critical current, I-c(sf), of a superconducting wire can be defined in a more fundamental way than the conventional (and arbitrary) electric field criterion, E-c =1 mu V/cm. We defined I-c(sf) as the threshold current,Ic,B, at which the perpendicular component of the local magnetic flux density, B-perpendicular to, measured at any point on the surface of a high-temperature superconducting tape abruptly crosses over from a non-linear to a linear dependence with increasing transport current. This effect results from the current distribution across the tape width progressively transitioning from non-uniform to uniform. The completion of this progressive transition was found to be singular. It coincides with the first discernible onset of dissipation and immediately precedes the formation of a measureable electric field. Here, we show that the same I-c,I-B definition of critical currents applies in the presence of an external applied magnetic field, B-a. In all experimental data presented here I-c,I-B is found to be significantly (10-30%) lower than I-c,I-E determined by the common electric field criterion of E-c =1 mu V/cm, and E-c to be up to 50 times lower at I-c,I-B than at I-c,I-E.