Structural modulation in bismuth cuprate superconducting film with continuous epitaxial growth

X-ray reciprocal space mapping (XRSM) revealed asymmetric intensity distribution of satellite peaks, caused by structural modulation, so-called supercell (SC), of the bismuth cuprate film Bi2Sr2Ca1Cu2OxBi2Sr2Ca1Cu2Ox (Bi-2212). How unit cells are distorted to form SC is investigated on multilayered structure, which induces extra strain into unit cells. In order to investigate the effect of displacement of relatively heavy   bismuth on intensity and distribution of SC peaks on XRSM, modulation waves were applied into not the whole crystal but to specified atoms constructing structural modulation as a simple crystal model, and the simulation was compared to the experimental results. To the contrary to multilayer, in this study, relatively thick films were prepared, which released the strain in its single layer. Epitaxial growth was verified by X-ray diffraction with relation of 32∘32∘ rotation with respect to the surface normal of the initial epitaxial Bi-2212 film.