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Title: Structural, electronic and magnetic properties of the series of double perovskites (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6}

Polycrystalline samples of the series of double perovskites Sr{sub 2−x}La{sub x}FeIrO{sub 6} were synthesized. Their structural, electronic and magnetic properties were investigated by X-ray powder diffraction, Mössbauer spectroscopy, magnetic susceptibility, heat capacity and electrical resistivity experiments. The compounds crystallize in a monoclinic structure and were fitted in space group P2{sub 1}/n, with a significant degree of Fe/Ir cationic disorder. As in Ca{sub 2−x}La{sub x}FeIrO{sub 6} the Sr-based system seems to evolve from an antiferromagnetic ground state for the end members (x=0.0 and x=2.0) to a ferrimagnetic order in the intermediate regions (x∼1). Since Mössbauer spectra indicate that Fe valence remains 3+ with doping, this tendency of change in the nature of the microscopic interaction could be attributed to Ir valence changes, induced by La{sup 3+} electrical doping. Upon comparing both Ca and Sr series, Sr{sub 2−x}La{sub x}FeIrO{sub 6} is more structurally homogenous and presents higher magnetization and transition temperatures. Magnetic susceptibility measurements at high temperatures on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6} indicate a very high ferrimagnetic Curie temperature T{sub C}∼700K. For the Sr{sub 2}FeIrO{sub 6} compound, electrical resistivity experiments under applied pressure suggest that this material might be a Mott insulator. - Graphical abstract: The Weiss constant as a function ofmore » La doping for the (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6} series, indicating changes in Fe–Ir magnetic coupling on both families. - Highlights: • The double perovskite series (Ca,Sr){sub 2−x}La{sub x}FeIrO{sub 6} were synthesized. • Changes in the Fe-Ir magnetic coupling due to La doping on both series. • Evidence of high T{sub C} on Sr{sub 1.2}La{sub 0.8}FeIrO{sub 6}. • Indication of Mott insulator behavior on Sr{sub 2}FeIrO{sub 6}.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ; ; ;  [6] ;  [2]
  1. Instituto de Física, Universidade Federal de Goiás, 74001-970 Goiânia, GO (Brazil)
  2. Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859 Campinas, SP (Brazil)
  3. Instituto de Física, Universidade Federal de Uberlândia, 38400-902 Uberlândia, MG (Brazil)
  4. Núcleo de Física, Universidade Federal de Sergipe, Campus Itabaiana, 49500-000 Itabaiana, SE (Brazil)
  5. Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, 09210-170 Santo André, SP (Brazil)
  6. Centro Brasileiro de Pesquisas Físicas, 22290-180 Rio de Janeiro, RJ (Brazil)
Publication Date:
OSTI Identifier:
22334159
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 212; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; ANTIFERROMAGNETISM; ELECTRIC CONDUCTIVITY; FERRIMAGNETISM; GROUND STATES; INTERACTIONS; LANTHANUM IONS; MAGNETIC SUSCEPTIBILITY; MAGNETIZATION; MONOCLINIC LATTICES; PEROVSKITE; POLYCRYSTALS; SPECTRA; SPECTROSCOPY; X-RAY DIFFRACTION