Large orbital polarization in nickelate-cuprate heterostructures by dimensional control of oxygen coordination.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30718483.
- Also identified by DOI 10.1038/s41467-019-08472-y and PMC identifier 6362240.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Artificial heterostructures composed of dissimilar transition metal oxides provide unprecedented opportunities to create remarkable physical phenomena. Here, we report a means to deliberately control the orbital polarization in LaNiO<sub>3</sub> (LNO) through interfacing with SrCuO<sub>2</sub> (SCO), which has an infinite-layer structure for CuO<sub>2</sub>. Dimensional control of SCO results in a planar-type (P-SCO) to chain-type (C-SCO) structure transition depending on the SCO thickness. This transition is exploited to induce either a NiO<sub>5</sub> pyramidal or a NiO<sub>6</sub> octahedral structure at the SCO/LNO interface. Consequently, a large change in the Ni d orbital occupation up to ~30% is achieved in P-SCO/LNO superlattices, whereas the Ni e<sub>g</sub> orbital splitting is negligible in C-SCO/LNO superlattices. The engineered oxygen coordination triggers a metal-to-insulator transition in SCO/LNO superlattices. Our results demonstrate that interfacial oxygen coordination engineering provides an effective means to manipulate the orbital configuration and associated physical properties, paving a pathway towards the advancement of oxide electronics.