Nanostructure science and vortex physics of YBa2Cu3O7 for practical high-performance coated conductor

YBa₂Cu₃O₇ coated conductors are under active development for high-field magnet, nuclear magnetic resonance, and fusion energy applications. Extensive research efforts have focused on enhancing the performance of these conductors. Among these, significant attention has been given to vortex physics, nanoscale science, and process optimization. Grain boundaries, which act as weak link, degrade the critical current density. To mitigate this, YBa₂Cu₃O₇ films are deposited on textured metal substrates with highly oriented buffer layers. To further enhance the critical current density, nanoscale pinning centers are incorporated via self-organization during film growth. The critical current density is governed by multiscale factors involving the nanorod structure at atomic, nanoscale, and micrometer levels. Nanorod morphology and density are controlled, and additional types of pinning centers are introduced to prepare hybrid pinning centers. These nanorods alter the chemical bonding and electronic structure of YBa₂Cu₃O₇ at their interfaces. The influence of nanocomposite formation on the superconducting transition temperature is discussed based on oxygen vacancies formation induced by tensile strain. Atomic scale nature of nanostructure and macroscopic homogeneity of properties related to the process variation should be investigated to advance the coated conductor technology. The integration of advanced characterization techniques, computational simulations, and artificial intelligence technology is effective in achieving a deeper understanding and more precise control of the underlying vortex pinning and the macroscopic phenomena caused by process variation.

Graphical abstract