Propagation control of octahedral tilt in SrRuO3 via artificial heterostructuring

TL;DR

This paper introduces a novel superlattice engineering method to control octahedral tilt propagation in SrRuO3, enabling precise manipulation of its magnetic properties without altering other structural parameters.

Contribution

The study develops a new approach to engineer octahedral tilt propagation in SrRuO3/SrTiO3 superlattices, allowing selective control of bonding geometry and functional properties.

Findings

Controlled RuO6 octahedral tilting via layer thickness variation

Significant enhancement of Ru magnetic moment

Decoupling of tilt propagation from lattice parameter changes

Abstract

Bonding geometry engineering of metal-oxygen octahedra is a facile way of tailoring various functional properties of transition metal oxides. Several approaches, including epitaxial strain, thickness, and stoichiometry control, have been proposed to efficiently tune the rotation and tilting of the octahedra, but these approaches are inevitably accompanied by unnecessary structural modifications such as changes in thin-film lattice parameters. In this study, we propose a method to selectively engineer the octahedral bonding geometries, while maintaining other parameters that might implicitly influence the functional properties. A concept of octahedral tilt propagation engineering has been developed using atomically designed SrRuO3/SrTiO3 superlattices. In particular, the propagation of RuO6 octahedral tilting within the SrRuO3 layers having identical thicknesses was systematically controlled by varying the thickness of adjacent SrTiO3 layers. This led to a substantial modification in the electromagnetic properties of the SrRuO3 layer, significantly enhancing the magnetic moment of Ru. Our approach provides a method to selectively manipulate the bonding geometry of strongly correlated oxides, thereby enabling a better understanding and greater controllability of their functional properties.