Optical Anisotropy of SrTiO3(110) for Different Surface Terminations

Abstract

In this work we investigate the SrTiO3(110) surface by reflectance anisotropy spectroscopy (RAS) at varying preparation steps including ex situ wet etching, high temperature oxygen annealing, as well as in situ vacuum annealing. Different surface terminations show distinctly different RAS spectra which are correlated to an altered surface stoichiometry measured by X‐ray photoelectron spectroscopy (XPS) and an altered valence band structure measured by UV‐photoelectron spectroscopy (UPS) in cases of conductive samples. We link the changes in the observed RAS spectra to various surface reconstructions, with particular focus of the signature of (3 × 1) and (1 × 4) reconstructed surfaces, and a metallic surface state observed in vacuum annealed SrTiO3.