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Title: Magnetism and Metal-Insulator Transition in Oxygen Deficient SrTiO3

First-principles calculations to study the electronic and magnetic properties of bulk, oxygen-deficient SrTiO3 (STO) under different doping conditions and densities have been conducted. The appearance of magnetism in oxygen-deficient STO is not determined solely by the presence of a single oxygen vacancy but by the density of free carriers and the relative proximity of the vacant sites. We find that while an isolated vacancy behaves as a nonmagnetic double donor, manipulation of the doping conditions allows the stability of a single-donor state, with emergent local moments coupled ferromagnetically by carriers in the conduction band. Strong local lattice distortions enhance the binding of this state. The energy of the in-gap local moment can be further tuned by orthorhombic strain. Consequently we find that the free-carrier density and strain are fundamental components to obtaining trapped spin-polarized electrons in oxygen-deficient STO, which may have important implications in the design of optical devices.
Authors:
 [1] ;  [2] ;  [3]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, IL (United States)
Publication Date:
OSTI Identifier:
1215569
Grant/Contract Number:
AC02-06CH11357; AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 92; Journal ID: ISSN 1098-0121
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