Modulated structure of Bi-Sr-Ca-Cu-O thin films on Y 3Al 5O 12 (YAG) substrate

Abstract

Superconducting Bi-Sr-Ca-Cu-O thin films were prepared on Y 3Al 5O 12 (YAG) single-crystal substrates by metalorganic chemical vapor deposition (MOCVD). The modulated structure of these Bi-Sr-Ca-Cu-O thin films was characterized by cross-sectional high-resolution electron microscopy (HREM) and electron diffraction. The period of this modulated structure at the interface on the YAG substrate was about 24 Å, which is twice the lattice constant of the YAG substrate (12.005 Å). We examined the microstructure of the interface between Bi-Sr-Ca-Cu-O thin films and the YAG substrate from the viewpoint of the long-range coincidence through the modulation period.