Research Update: Interface-engineered oxygen octahedral tilts in perovskite oxide heterostructures

Daisuke Kan,Ryotaro Aso,Hiroki Kurata,Yuichi Shimakawa

doi:10.1063/1.4918965

Abstract

Interface engineering of structural distortions is a key for exploring the functional properties of oxide heterostructures and superlattices. In this paper, we report on our comprehensive investigations of oxygen octahedral distortions at the heterointerface between perovskite oxides SrRuO3 and BaTiO3 on GdScO3 substrates and of the influences of the interfacially engineered distortions on the magneto-transport properties of the SrRuO3 layer. Our state-of-the-art annular bright-field imaging in aberration-corrected scanning transmission electron microscopy revealed that the RuO6 octahedral distortions in the SrRuO3 layer have strong dependence on the stacking order of the SrRuO3 and BaTiO3 layers on the substrate. This can be attributed to the difference in the interfacial octahedral connections. We also found that the stacking order of the oxide layers has a strong impact on the magneto-transport properties, allowing for control of the magnetic anisotropy of the SrRuO3 layer through interface engineering. Our results demonstrate the significance of the interface engineering of the octahedral distortions on the structural and physical properties of perovskite oxides.

Highlights

We report on our comprehensive investigations of oxygen octahedral distortions at the heterointerface between perovskite oxides SrRuO3 and BaTiO3 on GdScO3 substrates and of the influences of the interfacially engineered distortions on the magneto-transport properties of the SrRuO3 layer
We found that the stacking order of the oxide layers has a strong impact on the magnetotransport properties, allowing for control of the magnetic anisotropy of the SrRuO3 layer through interface engineering
Our results demonstrate the significance of the interface engineering of the octahedral distortions on the structural and physical properties of perovskite oxides

Summary

Introduction

To understand the influences of the BTO bottom and upper layers on the SRO layer structure, we evaluated the oxygen octahedral tilt angle θ tilt and in-plane oxygen displacement ∆x as a function of the atomic position in the heterostructures. For the SRO/BTO/GSO heterostructure (Fig. 3(a)), the octahedral tilt is strongly suppressed across the BTO/GSO interface.

Results

Conclusion