Interface properties and failures of REBCO coated conductor tapes: Research progress and challenges

RE-Ba-Cu-O (REBCO, where RE = Y, Gd, Sm, and other rare earth elements) coated conductor (CC) tapes are promising for applications in high-energy physics and high-field science owing to their significant advantages such as high critical magnetic field, high current density, and the ability to achieve superconductivity at liquid nitrogen temperatures. Nevertheless, the mechanical and superconducting performances of these CC tapes are significantly affected by interface failures, such as interfacial delamination and coating fractures, which arise from the complex interplay of mechanical stress induced by magnet processing, thermal mismatch stress during cooling, electromagnetic stress under high magnetic fields, and thermal stress during quenching. This study comprehensively reviews the interface properties and failure behavior of REBCO CC tapes. First, the research progress in characterizing the intricate interface properties of REBCO CC is systematically reviewed. Furthermore, the interface failure behavior in extreme multifield environments was analyzed and summarized. Subsequently, this study outlines optimization strategies to mitigate interface failure risks in REBCO supercon-ducting magnet structures. Finally, we address the current challenges and future perspectives on interface issues in REBCO CC tapes. By addressing these challenges, this study offers valuable insights for advancing the development and practical implementation of superconducting technologies in diverse applications.