Dimensional Control of Octahedral Tilt in SrRuO3 via Infinite-Layered Oxides

Manipulation of octahedral distortion at atomic scale is an effective means to tune the ground states of functional oxides. Previous work demonstrates that strain and film thickness are variable parameters to modify the octahedral parameters. However, selective control of bonding geometry by structural propagation from adjacent layers is rarely studied. Here we propose a new route to tune the ferromagnetism in SrRuO3 (SRO) ultrathin layers by oxygen coordination of adjacent SrCuO2 (SCO) layers. The infinite-layered CuO2 exhibits a structural transformation from planar-type to chain-type with reduced film thickness. Two orientations dramatically modify the polyhedral connectivity at the interface, thus altering the octahedral distortion of SRO. The local structural variation changes the spin state of Ru and orbital hybridization strength, leading to a significant change in the magnetoresistance and anomalous Hall resistivity. These findings could launch investigations into adaptive control of functionalities in quantum oxide heterostructures using oxygen coordination.

Automated summary

Previous studies have shown that manipulation of octahedral distortion at atomic level is an effective means to tune the ground states of functional oxides. This study proposes a new route to tune ferromagnetism in ultrathin SrRuO3 layers by oxygen coordination of adjacent SrCuO2 layers, altering octahedral distortion and spin state of Ru.