Reversible Transition Between Thermodynamically Stable Phases with Low Density of Oxygen Vacancies on SrTiO$_3$(110) Surface

TL;DR

This study investigates the reversible phase transition of SrTiO$_3$(110) surfaces between two reconstructed phases, controlled by surface metal concentration, revealing low oxygen vacancy density on the stable surface.

Contribution

It combines experimental STM and DFT calculations to elucidate the atomic structures and phase stability mechanisms of SrTiO$_3$(110) surface reconstructions.

Findings

Reversible phase transition between (4×1) and (5×1) structures controlled by surface metal levels.

DFT confirms phase stability depends on chemical potential of Sr and Ti.

Stable surface exhibits low oxygen vacancy density.

Abstract

The surface reconstruction of SrTiO$_3$(110) is studied with scanning tunneling microscopy and density functional theory (DFT) calculations. The reversible phase transition between (4$\times$1) and (5$\times$1) is controlled by adjusting the surface metal concentration [Sr] or [Ti]. Resolving the atomic structures of the surface, DFT calculations verify that the phase stability changes upon the chemical potential of Sr or Ti. Particularly, the density of oxygen vacancies is low on the thermodynamically stabilized SrTiO$_3$(110) surface.