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Title: Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5)

Abstract

New oxides of general formula Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5) have been synthesized as polycrystalline materials and characterized structurally by X-ray diffraction. For 0.5{<=}x<0.67 the orthorhombic, Pnma, perovskite structure of the end member, SrRuO{sub 3}, is found. At x=0.67 a phase separation into an Ru-rich Pnma phase and a Co-rich I2/c phase occurs. The I2/c form is also found for x=1.0 but another orthorhombic phase, Imma, obtains for x=1.33 and 1.5. Reductive weight losses indicate negligible oxygen non-stoichiometry, i.e., {delta}{approx}0, for all compositions even those rich in Co. High-resolution electron energy loss spectroscopy (EELS) indicates that cobalt is high-spin Co{sup 3+} or high-spin Co{sup 4+} for all x. Appropriate combinations of Ru{sup 4+}, Ru{sup 5+}, HS Co{sup 3+} and HS Co{sup 4+} are proposed for each x which are consistent with the observed Ru(Co)-O distances. Significant amounts of Co{sup 4+} must be present for large x values to explain the short observed distances. Broad maxima in the d.c. susceptibilities are found between 78 and 97 K with increasing x, along with zero-field-cooled (ZFC) and field-cooled (FC) divergences suggesting glassy magnetic freezing. A feature near 155 K for all samples indicates a residualmore » amount of ferromagnetic SrRuO{sub 3} not detected by X-ray diffraction. - Graphical abstract: Correlation between the average B-site radius, the Goldschmidt tolerance factor and the sequence of space groups and Glazer tilt systems found for the perovskite solid solution Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6}.« less

Authors:
 [1];  [2];  [3];  [1];  [2];  [4];  [5];  [1];  [1]
  1. Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ont., L8S 4M1 (Canada)
  2. (Canada)
  3. (Spain), E-mail: lozano@mcmaster.ca
  4. Departamento de Quimica Inorganica, Universidad de La Laguna, 38206-La Laguna, Tenerife (Spain)
  5. Departamento de Fisica Fundamental II, Universidad de La Laguna, 38200-La Laguna, Tenerife (Spain)
Publication Date:
OSTI Identifier:
21015766
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 180; Journal Issue: 4; Other Information: DOI: 10.1016/j.jssc.2007.01.019; PII: S0022-4596(07)00036-9; Copyright (c) 2007 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; COBALT COMPOUNDS; COBALT IONS; ENERGY-LOSS SPECTROSCOPY; ION MICROPROBE ANALYSIS; MAGNETISM; MONOCLINIC LATTICES; ORTHORHOMBIC LATTICES; OXIDES; OXYGEN; PEROVSKITE; POLYCRYSTALS; RUTHENIUM COMPOUNDS; RUTHENIUM IONS; SOLID SOLUTIONS; SOLUBILITY; SPACE GROUPS; SPIN; STRONTIUM COMPOUNDS; TETRAGONAL LATTICES; X-RAY DIFFRACTION

Citation Formats

Lozano-Gorrin, A.D., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Departamento de Quimica Inorganica, Universidad de La Laguna, 38206-La Laguna, Tenerife, Greedan, J.E., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Nunez, P., Gonzalez-Silgo, C., Botton, G.A., and Radtke, G.. Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5). United States: N. p., 2007. Web. doi:10.1016/j.jssc.2007.01.019.
Lozano-Gorrin, A.D., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Departamento de Quimica Inorganica, Universidad de La Laguna, 38206-La Laguna, Tenerife, Greedan, J.E., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Nunez, P., Gonzalez-Silgo, C., Botton, G.A., & Radtke, G.. Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5). United States. doi:10.1016/j.jssc.2007.01.019.
Lozano-Gorrin, A.D., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Departamento de Quimica Inorganica, Universidad de La Laguna, 38206-La Laguna, Tenerife, Greedan, J.E., Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1, Nunez, P., Gonzalez-Silgo, C., Botton, G.A., and Radtke, G.. Sun . "Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5)". United States. doi:10.1016/j.jssc.2007.01.019.
@article{osti_21015766,
title = {Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5)},
author = {Lozano-Gorrin, A.D. and Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1 and Departamento de Quimica Inorganica, Universidad de La Laguna, 38206-La Laguna, Tenerife and Greedan, J.E. and Department of Chemistry, McMaster University, 1280 Main Street W., Hamilton, Ont., L8S 4M1 and Nunez, P. and Gonzalez-Silgo, C. and Botton, G.A. and Radtke, G.},
abstractNote = {New oxides of general formula Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6-} {sub {delta}} (0.5{<=}x{<=}1.5) have been synthesized as polycrystalline materials and characterized structurally by X-ray diffraction. For 0.5{<=}x<0.67 the orthorhombic, Pnma, perovskite structure of the end member, SrRuO{sub 3}, is found. At x=0.67 a phase separation into an Ru-rich Pnma phase and a Co-rich I2/c phase occurs. The I2/c form is also found for x=1.0 but another orthorhombic phase, Imma, obtains for x=1.33 and 1.5. Reductive weight losses indicate negligible oxygen non-stoichiometry, i.e., {delta}{approx}0, for all compositions even those rich in Co. High-resolution electron energy loss spectroscopy (EELS) indicates that cobalt is high-spin Co{sup 3+} or high-spin Co{sup 4+} for all x. Appropriate combinations of Ru{sup 4+}, Ru{sup 5+}, HS Co{sup 3+} and HS Co{sup 4+} are proposed for each x which are consistent with the observed Ru(Co)-O distances. Significant amounts of Co{sup 4+} must be present for large x values to explain the short observed distances. Broad maxima in the d.c. susceptibilities are found between 78 and 97 K with increasing x, along with zero-field-cooled (ZFC) and field-cooled (FC) divergences suggesting glassy magnetic freezing. A feature near 155 K for all samples indicates a residual amount of ferromagnetic SrRuO{sub 3} not detected by X-ray diffraction. - Graphical abstract: Correlation between the average B-site radius, the Goldschmidt tolerance factor and the sequence of space groups and Glazer tilt systems found for the perovskite solid solution Sr{sub 2}Ru{sub 2-} {sub x} Co {sub x} O{sub 6}.},
doi = {10.1016/j.jssc.2007.01.019},
journal = {Journal of Solid State Chemistry},
number = 4,
volume = 180,
place = {United States},
year = {Sun Apr 15 00:00:00 EDT 2007},
month = {Sun Apr 15 00:00:00 EDT 2007}
}