Evolution of the Surface Structures on SrTiO$_3$(110) Tuned by Ti or Sr Concentration

TL;DR

This study investigates how the surface structures of SrTiO$_3$(110) can be reversibly tuned by varying Ti or Sr concentrations, revealing different reconstructions and their electronic properties through microscopy and spectroscopy.

Contribution

It demonstrates controlled, reversible tuning of SrTiO$_3$(110) surface reconstructions via sputtering and evaporation, linking surface composition to structural and electronic changes.

Findings

Reversible surface phase transitions between multiple reconstructions.

Surface electronic structures vary with different surface reconstructions.

Surface metal concentration determines thermodynamic equilibrium structure.

Abstract

The surface structure of the SrTiO$_3$(110) polar surface is studied by scanning tunneling microscopy and X-ray photoelectron spectroscopy. Monophased reconstructions in (5$\times$1), (4$\times$1), (2$\times$8), and (6$\times$8) are obtained, respectively, and the evolution between these phases can be tuned reversibly by adjusting the Ar$^{+}$ sputtering dose or the amount of Sr/Ti evaporation. Upon annealing, the surface reaches the thermodynamic equilibrium that is determined by the surface metal concentration. The different electronic structures and absorption behaviors of the surface with different reconstructions are investigated.