Atomic structures of the defective SrTiO3 (001) surface

Surface structures of defective SrTiO(3) (001) have been studied by using scanning probe microscopy and density functional theory calculations. We observed several defective surface structures with true atomic resolution under reducing ultrahigh vacuum conditions. It is found that all the defects are terminated by (001), (100) and (010) microfacets of the TiO(2) plane. We propose microfaceting TiO(2) termination with Sr adatom models. The formation of various types of defects is driven by the changes of the surface stoichiometry depending on surface preparations.