Relevant Pinning for ab-Plane Jc Enhancement of MOCVD REBCO Coated Conductors

• Published in: IEEE transactions on applied superconductivity 2017-06, Vol.27 (4), p.1-5
• Main Authors: Xu, Aixia, Zhang, Yuan, Gharahcheshmeh, Meysam Heydari, Delgado, Louis, Khatri, Narayan, Liu, Yuhao, Galstyan, Eduard, Selvamanickam, Venkat
• Format: Article
• Language: English
• Subjects: ab-plane pinning; Conductors; Magnetic fields; MOCVD; RE2O3 precipitate arrays; REBCO coated conductors; Stacking; stacking faults; Superconducting magnetic energy storage; weak uncorrelated pinning; X-ray scattering
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2017.2648121

For REBa 2 Cu 3 O x (REBCO, where RE = rare earth) coated conductor applications, the prominence of the background magnetic field H in the orientation of ab-plane urges an immediate and proper understanding of the ab-plane pinning and in turn, the critical current density J c tuning. In this work, we present our ab-plane pinning study of metal organic chemical vapor deposited (MOCVD) REBCO coated conductors based on our previous observation of a strong linear correlation between J c at 77 K and J c at lower temperatures T and higher magnetic fields H. In this work, we found that, below ~40 K, besides the weak uncorrelated pinning, the intrinsic pinning due to the layered crystal structure of REBCO with charge reservoir CuO planes also plays an essential role for J c (T, H||ab). Such intrinsic pinning is independent of H, and increases with decreasing T. Combined with the microstructure and J c (T, H, θ) analysis, we found that, at T above ~40 K, strong correlated pinning centers, such as stacking faults and RE 2 O 3 precipitates, govern J c (T, H||ab). Our work provides an understanding of ab-plane pinning in Zr-added REBCO coated conductors and guidance for further J c (T, H) enhancement.