In:
Nature Communications, Springer Science and Business Media LLC, Vol. 9, No. 1 ( 2018-06-07)
Abstract:
The nature of the metal-insulator transition in thin films and superlattices of LaNiO 3 only a few unit cells in thickness remains elusive despite tremendous effort. Quantum confinement and epitaxial strain have been evoked as the mechanisms, although other factors such as growth-induced disorder, cation non-stoichiometry, oxygen vacancies, and substrate–film interface quality may also affect the observable properties of ultrathin films. Here we report results obtained for near-ideal LaNiO 3 films with different thicknesses and terminations grown by atomic layer-by-layer laser molecular beam epitaxy on LaAlO 3 substrates. We find that the room-temperature metallic behavior persists until the film thickness is reduced to an unprecedentedly small 1.5 unit cells (NiO 2 termination). Electronic structure measurements using X-ray absorption spectroscopy and first-principles calculation suggest that oxygen vacancies existing in the films also contribute to the metal-insulator transition.
Type of Medium:
Online Resource
ISSN:
2041-1723
DOI:
10.1038/s41467-018-04546-5
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2018
detail.hit.zdb_id:
2553671-0
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