Superconducting Characteristics of REBCO Coated Conductors With Different Zr Content

In this paper, REBa
₂
Cu
₃
O
_7-δ
(RE = rare earth elements, REBCO) coated conductors with different content of self-assembled BaZrO
₃
nanorods were grown by metal organic chemical vapor deposition using a roll-to-roll process. Small changes in chemical composition affecting Ba to Cu stoichiometry induce variation in REBCO c-axis lattice parameter and highly affect the self-field J
_c
at 77 K, superconducting transition width (ΔT
_c
), and in-field performance of coated conductors. While the self-field J
_c
at 77 K in 15 mol.% Zr-added REBCO film (5 MA cm
^-2
) was about 28% higher than that in 25 mol.% Zr-added REBCO (3.9 MA cm
^-2
), the in-field J
_c
at 30 K, 3 T (B∥c) of the latter was found to be 36% higher than that of the former. The high J
_c
values of 14.9 and 20.3 MA cm
^-2
at 30 K, 3 T (B∥c) were obtained in coated conductors with the c-axis lattice parameter of 11.74 and 11.76 Å in 15 and 25 mol.% Zr-added REBCO films, respectively.