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S. Gerhold, Z. Wang, M. Schmid, U. Diebold:
"Stoichiometry-driven switching between surface reconstructions on SrTiO₃(001)";
Surface Science, 621 (2014), 1 - 4.

Controlling the surface structure on the atomic scale is amajor difficulty for most transition metal oxides; this is
especially true for the ternary perovskites. The influence of surface stoichiometry on the atomic structure of the
SrTiO3(001) surface was examined with scanning tunneling microscopy, low-energy electron diffraction, lowenergy
He+ ion scattering (LEIS), and X-ray photoelectron spectroscopy (XPS). Vapor deposition of 0.8monolayer
(ML) strontium and 0.3 ML titanium, with subsequent annealing to 850 °C in 4 × 10−6 mbar O2, reversibly
switches the surface between c(4 × 2) and (2 × 2) reconstructions, respectively. The combination of LEIS and
XPS shows a different stoichiometry that is confined to the top layer. Geometric models for these reconstructions
need to take into account these different surface compositions.

Scanning tunneling microscopy Low energy electron diffraction Low energy ion scattering X-ray photoelectron spectroscopy Surface stoichiometry Strontium titanate