Evaluation of Critical Current for REBCO Coated Conductor Under Various Tensile Strains and Magnetic Field Angles

REBa2Cu3Ox (REBCO, RE: Y or rare-earth element) coated conductors (CCs) have a high critical current (I-c) density in a high magnetic field at low temperatures. Therefore, REBCO CCs are being studied for high-magnetic-field applications. I-c of REBCO CCs varies with the field angle and strain. The mechanism of the strain effect on the superconducting properties of REBCO CC is unclear. Thus, in this study, the relationship between the strain and other parameters for REBCO was studied to understand the strain effect of REBCO CC. The angular dependence of I-c for the REBCO CC under various tensile strains was investigated. A compact tensile testing apparatus for large transport-current measurements was developed. The field angular dependences of I-c for the REBCO CC were measured at a temperature of 77.3 K and magnetic field of 0.4 T, under several tensile strains. The I-c of the REBCO CC decreased due to the tensile strains at all field angles. The degradation was described by the strain effect of I-c as the magnetic fields parallel to the c-axis and the ab-plane varied with respect to the tensile strain. These results suggest that strains can control the variation in I-c and possibly the anisotropy of REBCO in the directions of the c-axis and ab-plane.

Automated summary

This study investigates the effect of strain on the superconducting properties of REBCO coated conductors, and finds that strain can control the variation in Ic and the anisotropy of REBCO in the directions of the c-axis and ab-plane.