High-Field and Angular Dependence Study of the Critical Current Surface in Modern REBCO Coated Conductors

In the frame of a collaboration between the University of Geneva and Tohoku University, the dependence of the critical current (Ic) on magnetic field orientation (Ө), intensity (B) and temperature (T) was characterized on three commercial REBCO tapes from Faraday Factory/SuperOx, SuperPower and Shanghai Superconductor Technology, at temperatures between 4.2 K and 77 K and in magnetic fields up to 19 T in Geneva and 24 T at Tohoku University. Measurements were performed on full-width tapes at University of Geneva, and on patterned microbridges at Tohoku University. Among the three examined tapes, significant variations in the anisotropic landscape of Ic(B,T,Ө) were observed (e.g. a single or dominant peak or a secondary peak rising with temperature), reflecting variations in processing methods and pinning centers. Additionally, results emphasize the necessity of full angular scans, as the angular position of the minimum Icis observed to depend on T and B and can occur at angles as low as 35°, challenging the typical assumption of the minimum located at 90°, when B is aligned to the c-axis of REBCO. To address such variability, preliminary fits at various T and B are calculated using the maximum entropy model, offering a promising pathway toward efficient scaling relations.