Controlling the surface structure on the atomic scale is a major 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, low-energy He+ ion scattering (LEIS), and X-ray photoelectron spectroscopy (XPS). Vapor deposition of 0.8 monolayer (ML) strontium and 0.3 ML titanium, with subsequent annealing to 850 {\deg}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.
@article{arxiv.1804.04472,
title = {Stoichiometry-driven switching between surface reconstructions on SrTiO$_3$(001)},
author = {Stefan Gerhold and Zhiming Wang and Michael Schmid and Ulrike Diebold},
journal= {arXiv preprint arXiv:1804.04472},
year = {2018}
}