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Journal of Materials Science

, Volume 30, Issue 5, pp 1245–1250 | Cite as

Nonstoichiometry and physical properties of the perovskite BaxLa1−xFeO3−y system

  • K. S. Roh
  • K. H. Ryu
  • C. H. Yo
Papers

Abstract

A series of samples in the BaxLa1−xFeO3−ysystem (x=0.00, 0.25, 0.50, 0.75, and 1.00) have been prepared at 1200°C under an atmospheric air pressure. The solid solutions of the system were analysed from the X-ray diffraction spectra and thermal analyses. X-ray diffraction studies assigned the compositions of the x=0.00 and 1.00 to the orthorhombic system and the compositions of the x=0.25, 0.50, and 0.75 to the cubic system. The reduced lattice volume increased with the x value in the system. The mole ratios of the Fe4+ ion in the solid solutions, or τ values, were determined by Mohr salt analyses and the non-stoichiometric chemical formulae of the system were formulated from the x, τ, and y values. From the results of the Mössbauer spectroscopy, the coordination and the magnetic property of the iron ion have been discussed. The electrical conductivities were measured as a function of temperature under atmospheric air pressure. The activation energy was minimum at the composition of x=0.50. The conduction mechanism can be explained by the hopping model between the mixed valences of the Fe3+ and Fe4+ ions.

Keywords

Activation Energy Electrical Conductivity Solid Solution Thermal Analysis Perovskite 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • K. S. Roh
    • 1
  • K. H. Ryu
    • 1
  • C. H. Yo
    • 1
  1. 1.Department of ChemistryYonsei UniversitySeoulKorea

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