The interface between single crystalline (001) LaAlO3 and (001) silicon

Atomic resolution high-angle annular dark-field imaging in scanning transmission electron microscopy is used to determine atomic arrangements at LaAlO3/Si interfaces, which were obtained by growing Si films epitaxially on (001) LaAlO3 single crystals. An unusual 3 x 1 interface reconstruction, in which every third La column is removed from the interface plane, is observed. The interface atomic structure is discussed in the context of electrically favorable interfacial bonding between the ionic oxide and Si.