Nanometer-scale striped surface terminations on fractured SrTiO$_{3}$ surfaces

TL;DR

This study uses cross-sectional scanning tunneling microscopy to reveal nanometer-scale striped surface terminations on fractured SrTiO$_{3}$, showing long-range alternating domains with distinct electronic structures, useful for complex oxide interface research.

Contribution

It demonstrates that room-temperature fracturing produces atomically smooth, striped surface domains with alternating terminations on SrTiO$_{3}$, enabling atomic-scale surface characterization.

Findings

Reproducible flat surfaces with striped domains were observed.

Domains exhibit distinct electronic structures.

TiO$_{2}$ and SrO terminations were identified.

Abstract

Using cross-sectional scanning tunneling microscopy on in situ fractured SrTiO$_{3}$, one of the most commonly used substrates for the growth of complex oxide thin films and superlattices, atomically smooth terraces have been observed on (001) surfaces. Furthermore, it was discovered that fracturing this material at room temperature results in the formation of stripe patterned domains having characteristic widths (~10 nm to ~20 nm) of alternating surface terminations that extend over a long-range. Spatial characterization utilizing spectroscopy techniques revealed a strong contrast in the electronic structure of the two domains. Combining these results with topographic data, we are able to assign both TiO$_{2}$ and SrO terminations to their respective domains. The results of this proof-of-principle experiment reveal that fracturing this material leads to reproducibly flat surfaces that can be characterized at the atomic-scale and suggests that this technique can be utilized for the study of technologically relevant complex oxide interfaces.