Structure, stability, and electronic properties of SrTiO3/LaAlO3 and SrTiO3/SrRuO3 interfaces

Density functional theory by means of the mixed-basis pseudopotential method was employed to carry out electronic-structure calculations of interfaces in SrTiO3/LaAlO3 and SrTiO3/SrRuO3 perovskite heterophase systems. The main objective of the work is to investigate the influence of different structural and chemical terminations of the interfaces on their electronic and adhesive properties. The investigated supercells therefore include not only interfaces with a regular perovskite stacking but also interfaces with planar stacking-fault-like defects of Ruddlesden-Popper and Magneli types. Stability of interfaces is assessed by calculating rigid and relaxed works of separation. Band offsets and Schottky barriers are determined for the insulator/insulator SrTiO3/LaAlO3 and the insulator/conductor SrTiO3/SrRuO3 systems, respectively.