Effect of oxygen deficiency on SrTiO_3(001) surface reconstructions

摘要

The contribution of oxygen deficiencies to SrTiO_3(001) surface reconstructions is studied using low-energy electron diffraction and scanning tunneling microscopy. We have prepared a SrTiO_3 sample with spatially graded oxygen deficiencies, in which R33.7°-(13~(1/2) × 13~(1/2)), (2 × 1), and R26.6°-(5~(1/2) × 5~(1/2)) surface reconstructions are observed while increasing the amount of oxygen deficiencies. This indicates that oxygen nonstoichiometry has an influence on the formation of various surface reconstructions as one of the important factors. This concept is also applicable to other transition metal oxides to prepare atomically ordered surfaces in a reproducible manner.