Nanoscale morphological features in the structural evolution of HTSC films of organometallic aerosols

Abstract

The evolution of the formation of a structure in high-temperature superconducting Bi₂Sr₂CaCu₂O₈ films obtained from organometallic aerosols is investigated by atomic force microscopy and scanning electron microscopy. Nanoscale granular supramolecular structures were found for the first time in the liquid-phase and pyrolytic stages. It is shown that pyrolytic processes occur within individual nanogranules. The minimum sizes of a nanogranule are 30–50 nm in base and 5 nm in height. In the high-order crystallization stage, epitaxial recrystallization occurs, as a result of which platelike crystallites are formed. They are 15–20 nm thick, have growth steps 1–5 nm in height, and are parallel to the substrate. The nonoriented morphological forms are individual three-dimensional crystallites up to 100 nm in size.