Atomic-Resolution Study Of Charge Transfer Effects At The Latio3/Lafeo3 Interface

Charge transfer effect can give rise to exotic two-dimensional phenomena at not only polar-nonpolar interfaces but also isopolar interfaces in complex oxides. Here, we investigate the valence state changes of both Ti and Fe at the LaTiO3/LaFeO3 interface by a combination of density functional theory calculations, molecular beam epitaxy, and aberration-corrected scanning transmission electron microscopy. We demonstrate that the charge transfer from Ti to Fe occurs near the interface. The majority of the transferred charge is located within 1 unit cell from the interface. Our results present a detailed understanding of the interfacial charge transfer effect upon the design of functional oxide heterostructures.