  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.
