In the past decades, REBa₂Cu₃O_7-δ (REBCO; RE = Y, rare earth element) second-generation high-temperature superconducting coated conductors have been considered one of the most promising superconducting materials. Thickening the REBCO superconducting layer is always one of the most challenge research directions due to the thickness effect. Thus, we innovatively developed a TFA-MOD-derived semi-grown technology to solved the problem of thickness effect below 4 μm thickness and achieve high performance. The corresponding I_c(77K, self-field) achieved 1100 A/12 mm-width. Furthermore, to improve the in-field flux pinning of REBCO films, the BaMO₃(M=Zr, Hf) nanocrystal addition strategy was extended to up-scaling thick REBCO coated conductors as long as hundreds of meters. The introduced monodispersed BaMO₃(M=Zr, Hf) nanocrystals with controllable sizes act as effective pinning centers to improve the in-field performance, which is identical to both the thin and thick films. It is revealed that the in-field I_c enhances to 290 A at 4.2 K@20 T and to 1450 A at 30 K@3 T for 4 mm-width tapes. Besides, more than 3 μm thick MOD-derived REBCO tapes were stably fabricated to hundreds of meters with high self-field and in-field performances with BaMO₃nanocrystal addition by the continuous MOD preparation line from Shanghai Creative Superconductor Technologies Co., Ltd.

The work is supported by the National Natural Science Foundation of China (52172271), the National Key R&D Program of China (2022YFE03150200), Shanghai Science and Technology Innovation Program (22511100200).

Keywords: High-temperature superconductor, REBa₂Cu₃O_7-δ, artificial flux pinning, nanocrystal addition