Ti- and Sr-rich surfaces of SrTiO3 studied by grazing incidence x-ray diffraction.

The structure of SrTiO₃ (100) (STO) single crystal surfaces has been investigated by grazing incidence x-ray diffraction. The authors found that chemically etched STO is composed ∼75% of an ideal TiO₂ surface layer and ∼25% of SrO and it is very stable when annealed in ultrahigh vacuum or in O₂ at high temperatures. A monolayer of SrO, epitaxially grown by pulsed laser deposition, is found to cover only a fraction of the TiO₂ layers and exhibits a 2×2 reconstruction with strong structural changes after annealing in conditions typically used for the deposition of oxides. [ABSTRACT FROM AUTHOR]