Water adsorption on SrTiO3(001): I. Experimental and simulated STM

• Published in: Surface science 2012-04, Vol.606 (7-8), p.762-765
• Main Authors: Becerra-Toledo, A.E., Castell, M.R., Marks, L.D.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Density functional theory; Exact sciences and technology; Micrographs; Photomicrographs; Physics; Reconstruction; Scanning; Scanning tunneling microscopy; Simulation; Strontium titanate; Surface chemistry; Surface reconstruction; Water adsorption
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2012.01.008

Density functional theory-based simulations of scanning tunneling micrographs were used for comparison to published experimental images of reconstructed SrTiO3(001) surfaces. It was found that the addition of dissociatively adsorbed H2O to the presently accepted structural solution of the 2×1 reconstruction is more consistent with the experimental data. A proposed model for the c(4×4) reconstruction, based on the hydrated 2×1 structure, agrees well with experiment and is consistent with a formation process consisting of the simple dehydration of a wet 2×1 structure. ► High-bias STM images of SrTiO3(001) reconstructions were simulated via DFT. ► Presently accepted 2×1 dry model is known to have a very high energy. ► A hydrated 2×1 model is more consistent with experimental STM than dry structure. ► A partially hydrated 2×1 is proposed as the structure of a c(4×4) reconstruction. ► This c(4×4) model agrees very well with experimental STM images.