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Title: Polarity compensation in ultra-thin films of complex oxides: The case of a perovskite nickelate

In this study, we address the fundamental issue of growth of perovskite ultra-thin films under the condition of a strong polar mismatch at the heterointerface exemplified by the growth of a correlated metal LaNiO 3 on the band insulator SrTiO 3 along the pseudo cubic [111] direction. While in general the metallic LaNiO 3 film can effectively screen this polarity mismatch, we establish that in the ultra-thin limit, films are insulating in nature and require additional chemical and structural reconstruction to compensate for such mismatch. A combination of in-situ reflection high-energy electron diffraction recorded during the growth, X-ray diffraction, and synchrotron based resonant X-ray spectroscopy reveal the formation of a chemical phase La 2Ni 2O 5 (Ni 2+) for a few unit-cell thick films. First-principles layer-resolved calculations of the potential energy across the nominal LaNiO 3/SrTiO 3 interface confirm that the oxygen vacancies can efficiently reduce the electric field at the interface.
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. University of Arkansas, Fayetteville, AR (United States). Dept. of Physics.
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 4; Journal ID: ISSN 2045-2322
Nature Publishing Group
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
36 MATERIALS SCIENCE; electronic properties and materials; surfaces; interfaces and thin films; surfaces, interfaces and thin films
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1241336