C(4 × 2) and related structural units on the SrTiO _3(001) surface: Scanning tunneling microscopy, density functional theory, and atomic structure

摘要

Density functional theory is used to simulate high-bias, constant-current scanning tunneling micrographs for direct comparison with experimental images. Coupled to previous spectroscopic data, these simulations are used to determine the atomic structure of Ti-rich nanostructures on strontium titanate (001) surfaces. These nanostructures have three consecutive TiO _x surface layers and exploit the distinctive structural motif of the c(4 × 2) reconstruction as their main building block. A structural model of a characteristic triline defect is also proposed.