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Title: Synthesis and properties of the double perovskites La{sub 2}NiVO{sub 6}, La{sub 2}CoVO{sub 6}, and La{sub 2}CoTiO{sub 6}

Abstract

The double perovskites La{sub 2}CoVO{sub 6}, La{sub 2}CoTiO{sub 6}, and La{sub 2}NiVO{sub 6}, are described. Rietveld fitting of neutron and powder X-ray diffraction data show La{sub 2}NiVO{sub 6} and La{sub 2}CoVO{sub 6} to have a disordered arrangement of B-cations whereas La{sub 2}CoTiO{sub 6} shows ordering of the B-cations (with {approx}5% Co/Ti inversion). Curie-Weiss fits to the linear region of the 1/{chi} plots reveal Weiss temperatures of -107, -34.8, and 16.3 K for La{sub 2}CoVO{sub 6}, La{sub 2}CoTiO{sub 6}, and La{sub 2}NiVO{sub 6}, respectively, and magnetic transitions are observed. La{sub 2}CoTiO{sub 6} prepared by our method differs from material prepared by lower-temperature routes. A simple antiferromagnetic spin model is consistent with the data for La{sub 2}CoTiO{sub 6}. These compounds are semiconductors with bandgaps of 0.41 (La{sub 2}CoVO{sub 6}), 1.02 (La{sub 2}CoTiO{sub 6}) and 0.45 eV (La{sub 2}NiVO{sub 6}). - Graphical abstract: The antiferromagnetic structure of La{sub 2}CoTiO{sub 6} as prepared by high-temperature routes with spins showing the P2/m' magnetic symmetry.

Authors:
 [1];  [2];  [3];  [3];  [4];  [4];  [2];  [4]
  1. Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States), E-mail: kholman@princeton.edu
  2. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)
  3. Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-952 Gdansk (Poland)
  4. Department of Chemistry, Princeton University, Princeton, NJ 08544 (United States)
Publication Date:
OSTI Identifier:
21015621
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 1; Other Information: DOI: 10.1016/j.jssc.2006.09.013; PII: S0022-4596(06)00512-3; Copyright (c) 2006 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; ANTIFERROMAGNETISM; COBALT COMPOUNDS; LANTHANUM COMPOUNDS; NEUTRON DIFFRACTION; NICKEL COMPOUNDS; OXIDES; PEROVSKITE; POWDERS; SEMICONDUCTOR MATERIALS; SPIN; SYMMETRY; SYNTHESIS; TITANIUM COMPOUNDS; VANADIUM COMPOUNDS; X-RAY DIFFRACTION

Citation Formats

Holman, K.L., Huang, Q., Klimczuk, T., Trzebiatowski, K., Bos, J.W.G., Morosan, E., Lynn, J.W., and Cava, R.J. Synthesis and properties of the double perovskites La{sub 2}NiVO{sub 6}, La{sub 2}CoVO{sub 6}, and La{sub 2}CoTiO{sub 6}. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2006.09.013.
Holman, K.L., Huang, Q., Klimczuk, T., Trzebiatowski, K., Bos, J.W.G., Morosan, E., Lynn, J.W., & Cava, R.J. Synthesis and properties of the double perovskites La{sub 2}NiVO{sub 6}, La{sub 2}CoVO{sub 6}, and La{sub 2}CoTiO{sub 6}. United States. doi:10.1016/j.jssc.2006.09.013.
Holman, K.L., Huang, Q., Klimczuk, T., Trzebiatowski, K., Bos, J.W.G., Morosan, E., Lynn, J.W., and Cava, R.J. Mon . "Synthesis and properties of the double perovskites La{sub 2}NiVO{sub 6}, La{sub 2}CoVO{sub 6}, and La{sub 2}CoTiO{sub 6}". United States. doi:10.1016/j.jssc.2006.09.013.
@article{osti_21015621,
title = {Synthesis and properties of the double perovskites La{sub 2}NiVO{sub 6}, La{sub 2}CoVO{sub 6}, and La{sub 2}CoTiO{sub 6}},
author = {Holman, K.L. and Huang, Q. and Klimczuk, T. and Trzebiatowski, K. and Bos, J.W.G. and Morosan, E. and Lynn, J.W. and Cava, R.J.},
abstractNote = {The double perovskites La{sub 2}CoVO{sub 6}, La{sub 2}CoTiO{sub 6}, and La{sub 2}NiVO{sub 6}, are described. Rietveld fitting of neutron and powder X-ray diffraction data show La{sub 2}NiVO{sub 6} and La{sub 2}CoVO{sub 6} to have a disordered arrangement of B-cations whereas La{sub 2}CoTiO{sub 6} shows ordering of the B-cations (with {approx}5% Co/Ti inversion). Curie-Weiss fits to the linear region of the 1/{chi} plots reveal Weiss temperatures of -107, -34.8, and 16.3 K for La{sub 2}CoVO{sub 6}, La{sub 2}CoTiO{sub 6}, and La{sub 2}NiVO{sub 6}, respectively, and magnetic transitions are observed. La{sub 2}CoTiO{sub 6} prepared by our method differs from material prepared by lower-temperature routes. A simple antiferromagnetic spin model is consistent with the data for La{sub 2}CoTiO{sub 6}. These compounds are semiconductors with bandgaps of 0.41 (La{sub 2}CoVO{sub 6}), 1.02 (La{sub 2}CoTiO{sub 6}) and 0.45 eV (La{sub 2}NiVO{sub 6}). - Graphical abstract: The antiferromagnetic structure of La{sub 2}CoTiO{sub 6} as prepared by high-temperature routes with spins showing the P2/m' magnetic symmetry.},
doi = {10.1016/j.jssc.2006.09.013},
journal = {Journal of Solid State Chemistry},
number = 1,
volume = 180,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
  • Ln{sub 2}CuSnO{sub 6} (Ln = Pr, Nd, and Sm) and La{sub 2}CuZrO{sub 6} have been stabilized in the same layered double perovskite structure as La{sub 2}CuSnO{sub 6} at high pressures of 6--8 GPa. Their crystal structures and magnetic properties were investigated. Replacement of La{sup 3+} by smaller lanthanide ions and Sn{sup 4+} by larger Zr{sup 4} increased the buckling of the Cu-O-Cu bonds in the CuO{sub 2} layers. In Nd{sub 2}CuSnO{sub 6}, both the Cu and Nd sublattice were found to exhibit weak ferromagnetism owing to spin canting. The magnetization data showed an anomalous transition at 110 K.
  • A series of osmium double perovskite oxides, Ln {sub 2}LiOsO{sub 6} (Ln=La, Pr, Nd, Sm), has been prepared as single crystals from acidic molten hydroxide. All four oxides crystallize in the monoclinic space group P2{sub 1}/n (Glazer tilt system no. 10, a {sup -} a {sup -} b {sup +}), forming a 1:1 ordered rock salt lattice of Li{sup +} and Os{sup 5+} cations. Magnetic susceptibility measurements show that these compounds are antiferromagnetic at low temperature with ordering temperatures of 39, 35, 23, and 32 K for Ln {sub 2}LiOsO{sub 6} (Ln=La, Pr, Nd, Sm), respectively. - Graphical abstract: Approximatemore » (110) view of the crystal structure of Pr{sub 2}LiOsO{sub 6} (representative of the series Ln {sub 2}LiOsO{sub 6} (Ln=La, Pr, Nd, Sm) consisting of OsO{sub 6} octahedra (striped) and LiO{sub 6} octahedra (gray). Praseodymium cations are shown as gray spheres and oxygen atoms as black spheres.« less
  • Highlights: ► La{sub 2}CrB{sub 2/3}Nb{sub 1/3}O{sub 6}, B = Mg, Ni, Cu perovskites adopt the GdFeO{sub 3} type structure. ► HREM and ED study indicating week ordering of B-cations for B = Mg. ► Antiferromagnetics with T{sub N} 90 (Mg), 125 (Ni) and 140 K (Ni). -- Abstract: The novel perovskites La{sub 2}CrB{sub 2/3}Nb{sub 1/3}O{sub 6}, B = Mg, Ni, and Cu have been synthesised at 1350 °C in air via the citrate route. Rietveld refinements using neutron powder diffraction (NPD) data showed that the compounds adopt the GdFeO{sub 3} type structure with space group Pbnm, and unit cell parametersmore » a≈b≈√(2)×a{sub p} and c ≈ 2 × a{sub p}, where a{sub p} ≈ 3.8 Å. Selected area electron diffraction (SAED) of B = Ni and Cu samples confirmed space group Pbnm. However, distinct reflections forbidden in Pbnm symmetry, but allowed in the monoclinic sub-group P2{sub 1}/n and unit cell parameters a≈b≈√(2)×a{sub p} and c ≈ 2 × a{sub p}, β ≈ 90° were present in SAED patterns of B = Mg sample. This indicates an ordering of the B-cations within the crystal structure of La{sub 2}CrMg{sub 2/3}Nb{sub 1/3}O{sub 6}. High-resolution electron microscopy (HREM) study indicating uniform, without formation of clusters, ordering of B-cations in the crystallites of La{sub 2}CrMg{sub 2/3}Nb{sub 1/3}O{sub 6}. Magnetic susceptibility measurements show that the compounds are antiferromagnetic (with some glass or spin clustering effects due to additional ferromagnetic interactions between the B-cations) with T{sub N} for La{sub 2}CrB{sub 2/3}Nb{sub 1/3}O{sub 6}, B = Mg, Ni, Cu being 90, 125 and 140 K, respectively.« less
  • Powder neutron and X-ray diffraction studies show that the double perovskites in the region 0=<x=<1 exhibit two crystallographic modifications at room temperature: monoclinic P2{sub 1}/n and tetragonal I4/m, with a boundary at 0.75<x<0.9. Magnetic susceptibility measurements indicate that for x=0 and 0.5 Sr{sub 2-x}La{sub x}MnWO{sub 6} orders antiferromagnetically (AFM) at 15 and 25K, respectively, for 0.75=<x<1.0, a contribution of weak ferromagnetism (FM), probably due to canted-AFM order, increases with increasing x. The end point compound SrLaMnWO{sub 6} shows the strongest FM cluster effect; however, no clear evidence of magnetic order is discernable down to 4.2K. X-ray absorption spectroscopy (XAS) confirmsmore » Mn{sup 2+} and mixed-valent W{sup 6+/5+} formal oxidation states in Sr{sub 2-x}La{sub x}MnWO{sub 6}.« less
  • 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 remainsmore » 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 of 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