Investigation of initial epitaxial growth of (Ba, Sr)TiO3 thin film on (0 0 1) SrTiO3 substrate using first-principles calculations

Initial epitaxial growth of (Ba, Sr)TiO3 (BST) thin film on (0 0 1) SrTiO3 (STO) substrate is investigated by first-principles calculations. Binding energy, density of state and bond populations are calculated for (AO) (A = Ba or Sr), (TiO) and (ATiO3) unit-cell layers deposition on (0 0 1) STO substrate based on layer-by-layer growth mode including SrO-terminated and TiO2-terminated surfaces. Three possible interfaces including Normal stacking interface, Ruddlesden–Popper-type interface and Magnéli-type interface are considered. It is found that BST thin film can epitaxially grow on (0 0 1) STO substrate with a two-layers growth mode. This work is crucial in theoretical understanding the epitaxial growth mechanism and preparing epitaxial thin films for perovskite ferroelectrics.

► Initial epitaxial growth of (Ba, Sr)TiO3 has been investigated by first-principles.
► BST thin film epitaxially grow on (0 0 1) STO substrate with a two-layers growth mode.
► Three possible interfaces were considered.