Investigation of initial epitaxial growth of (Ba, Sr)TiO_3 thin film on (001) SrTiO_3 substrate using first-principles calculations

摘要

Initial epitaxial growth of (Ba, Sr)TiO_3 (BST) thin film on (001) SrTiO_3 (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 (ATiO_3) unit-cell layers deposition on (001) STO substrate based on layer-by-layer growth mode including SrO-terminated and TiO_2-terminated surfaces. Three possible interfaces including Normal stacking interface, Ruddlesden-Popper-type interface and Magneli-type interface are considered. It is found that BST thin film can epitaxially grow on (001) 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.