Atomic and Electronic Structures of Correlated SrRuO3/SrTiO3 Superlattices

TL;DR

This study explores how atomic-scale epitaxy of SrRuO3/SrTiO3 superlattices allows precise control of atomic distortions, which in turn modulates their electronic structures, offering insights for designing advanced oxide electronic devices.

Contribution

It demonstrates the systematic control of octahedral distortions in SrRuO3/SrTiO3 superlattices and links these structural changes to electronic properties using advanced spectroscopy.

Findings

RuO6 octahedral distortion varies from 167° to 175° with STO layer thickness

Octahedral distortions influence Ti and Ru electronic structures

Atomic control enables tailored electronic properties in superlattices

Abstract

Atomic-scale precision epitaxy of perovskite oxide superlattices provides unique opportunities for controlling the correlated electronic structures, activating effective control knobs for intriguing functionalities including electromagnetic, thermoelectric, and electrocatalytic behaviors. In this study, we investigated the close interplay between the atomic and electronic structures of correlated superlattices synthesized by atomic-scale precision epitaxy. In particular, we employ superlattices composed of correlated magnetic SrRuO3 (SRO) and quantum paraelectric SrTiO3 (STO) layers. In those superlattices, RuO6 octahedral distortion is systematically controlled from 167 to 175 degrees depending on the thickness of the STO layers, also affecting the TiO6 octahedral distortion within the STO layer. Customized octahedral distortion within SRO/STO superlattices in turn modifies the electronic structures of both the Ti and Ru compounds, observed by X-ray absorption spectroscopy. Our results identify the close correlation between atomic lattice and electronic structures enabled by the facile controllability of atomic-scale epitaxy, which would be useful for designing future correlated oxide devices.