2006/03/28 by Hitoshi Seo, H. W. Seo, Q. Y. Chen +6
Materials Science · Physics and Astronomy · #Copper Interconnects and Reliability #FOS: Physical sciences #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con) #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/0603767
arxiv created 2006/03/28 · openalex publication_date 2006/03/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
X-ray photoemission spectroscopy has been used to investigate the depth dependent crystal structures and chemical compositions of sequentially chemical-etched YBa2Cu3O7-d (YBCO) ultrathin film superconductors. In the near-interface region the crystal structure is severely oxygen deficient and of tetragonal symmetry. We consider this a revelation of retarded oxygen diffusion into the O(1) sites during the post-deposition annealing in the presence of interface mismatch strain. Near the free surface, the oxygen-deficiency was much alleviated because of the partial strain relaxation and the crystal symmetry becomes orthorhombic. Compared with as-deposited films of equivalent thickness, which is less oxygen deficient and shows superconducting transition, the stripped-down near-interface layer exhibits no sign of superconductivity.