Dual Modulation Strategy for Suppressing the Thickness Effect in REBCO Coated Conductors
Xinyue Xia, Liangkang Chen, Zhongtang Xu, Guangyao Lin, Penghong Hu, Minghui Tang, Chao Yao, Lingkai Zhang, Ziheng Guo, Dongliang Gong, Chiheng Dong, Yue Gong, Yi Zhao, Lingxiao Zhao, Yanpeng Qi, Junyi Luo, Yuji Tsuchiya, Satoshi Awaji, Dongliang Wang, Xianping Zhang, Yanwei MaABSTRACT
High‐temperature superconducting coated conductors are pivotal for nuclear fusion and other transformative electrical applications. However, the current‐carrying capacity of these conductors remains insufficient to realize such large‐scale applications, as it is fundamentally constrained by the “thickness effect”, an intrinsic degradation of critical current density with increasing superconducting layer thickness. Here, we report a dual‐modulation strategy that overcomes this long‐standing hurdle in pulsed‐laser‐deposited (PLD) REBa 2 Cu 3 O x (REBCO, RE = rare earth) superconductors. By coupling dynamic thermal control with rare‐earth composition engineering, we effectively balance deposition flux and surface diffusion to maintain structural continuity, and suppress a ‐axis grain formation to obtain dense mixed‐dimensional artificial pinning centers. Our approach enables the growth of high‐quality REBCO layers up to 6 µm thick on technical substrates without a discernible “thickness effect”. The 6 µm‐thick coated conductors deliver unprecedented critical current of 2500 A/cm at 20 K and 10 T and 1446 A/cm at 50 K and 5 T, representing the highest values reported for all PLD‐grown REBCO conductors to date. Our results demonstrate significant performance enhancements by eliminating the “thickness effect” in REBCO films, providing a scalable route for high‐field and fusion for producing high‐temperature superconducting coated conductors that are favorable for large‐scale applications.