Three dimensional band-filling control of complex oxides triggered by interfacial electron transfer.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33907193.
- Also identified by DOI 10.1038/s41467-021-22790-0 and PMC identifier 8079372.
- 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
The d-band-filling of transition metals in complex oxides plays an essential role in determining their structural, electronic and magnetic properties. Traditionally, at the oxide heterointerface, band-filling control has been achieved via electrostatic modification in the structure of field-effect transistors or electron transfer, which is limited to the quasi-two-dimension at the interface. Here we report a three-dimensional (3D) band-filling control by changing the local lattice coordination in a designed oxide heterostructure. At the LaCoO<sub>3</sub>/LaTiO<sub>3</sub> heterointerface, due to the Fermi level mismatch, electrons transfer from LaTiO<sub>3</sub> to LaCoO<sub>3</sub>. This triggers destabilisation of the CoO<sub>6</sub> octahedrons, i.e. the formation of lattice configurations with a reduced Co valence. The associated oxygen migration results in the 3D topotactic phase transition of LaCoO<sub>3</sub>. Tuned by the thickness of LaTiO<sub>3</sub>, different crystalline phases and band-fillings of Co occur, leading to the emergence of different magnetic ground states.