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Title: Slater insulator in iridate perovskites with strong spin-orbit coupling

The perovskite SrIrO 3 is an exotic narrow-band metal owing to a confluence of the strengths of the spin-orbit coupling (SOC) and the electron-electron correlations. It has been proposed that topological and magnetic insulating phases can be achieved by tuning the SOC, Hubbard interactions, and/or lattice symmetry. Here, we report that the substitution of nonmagnetic, isovalent Sn 4+ for Ir 4+ in the SrIr 1–xSn xO 3 perovskites synthesized under high pressure leads to a metal-insulator transition to an antiferromagnetic (AF) phase at T N ≥ 225 K. The continuous change of the cell volume as detected by x-ray diffraction and the λ-shape transition of the specific heat on cooling through T N demonstrate that the metal-insulator transition is of second order. Neutron powder diffraction results indicate that the Sn substitution enlarges an octahedral-site distortion that reduces the SOC relative to the spin-spin exchange interaction and results in the type- G AF spin ordering below T N. Measurement of high-temperature magnetic susceptibility shows the evolution of magnetic coupling in the paramagnetic phase typical of weak itinerant-electron magnetism in the Sn-substituted samples. Furthermore, a reduced structural symmetry in the magnetically ordered phase leads to an electron gap opening at the Brillouinmore » zone boundary below T N in the same way as proposed by Slater.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [4] ;  [5] ;  [6] ;  [7] ;  [1] ;  [1] ;  [8] ;  [8] ;  [9] ;  [9] ;  [10] ;  [5] ;  [11] ;  [7] ;  [7]
  1. Chinese Academy of Sciences (CAS), Beijing (China)
  2. Chinese Academy of Sciences (CAS), Beijing (China); Univ. of Texas at Austin, Austin, TX (United States)
  3. RIKEN, Saitama (Japan)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  6. Univ. of Arkansas, Fayetteville, AR (United States)
  7. Univ. of Texas at Austin, Austin, TX (United States)
  8. Argonne National Lab. (ANL), Argonne, IL (United States)
  9. Univ. of Tokyo, Chiba (Japan)
  10. Rutgers Univ., Piscataway, NJ (United States)
  11. RIKEN, Saitama (Japan); RIKEN Advanced Institute for Computational Science (AICS), Hyogo (Japan); RIKEN Center for Emergent Matter Science (CEMS), Saitama (Japan)
Publication Date:
OSTI Identifier:
1330558
Grant/Contract Number:
AC05-00OR22725; AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 117; Journal Issue: 17; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY