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Title: Antiferromagnetic defect structure in LaNi O 3 δ single crystals

Here, the origins of the metal-insulator and magnetic transitions exhibited by perovskite rare-earth nickelates, RNiO 3 (where R is a rare-earth element), remain open issues, with charge disproportionation, magnetic interactions, and lattice response across multiple length scales being among the many possible origins. Recently, growth of single crystals of LaNiO 3, which is the only member of these compounds that remains metallic in its ground state, has been reported, opening a new chapter in the investigation of the perovskite nickelates. Here, using a combination of magnetometry, heat capacity, and neutron scattering on as-grown and purposely reduced LaNiO 3–δ crystals, we show that both antiferromagnetic and ferromagnetic phases with a Néel temperature of ~152 K and a Curie temperature of ~225 K can be induced by reduction of the oxygen content. Transmission electron microscopy shows that these phases are characterized by ordered oxygen vacancy defect structures that exist as dilute secondary phases in as-grown crystals despite growth in partial oxygen pressures up to at least 130 bar. The demonstration of antiferromagnetism resulting from oxygen vacancy ordered structures implies that stoichiometry must be explicitly considered when interpreting the bulk properties of LaNiO 3–δ single crystals; accordingly, the implications of our results formore » putative oxygen-stoichiometric LaNiO 3 are discussed.« less
Authors:
 [1] ;  [1] ;  [2] ; ORCiD logo [3] ; ORCiD logo [4] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Univ. of Illinois at Chicago, Chicago, IL (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review Materials
Additional Journal Information:
Journal Volume: 2; Journal Issue: 6; Journal ID: ISSN 2475-9953
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1454392
Alternate Identifier(s):
OSTI ID: 1441245