skip to main content

SciTech ConnectSciTech Connect

Title: Fergusonite-type CeNbO{sub 4+δ}: Single crystal growth, symmetry revision and conductivity

Large fergusonite-type (ABO{sub 4}, A=Ce, B=Nb) oxide crystals, a prototype electrolyte composition for solid oxide fuel cells (SOFC), were prepared for the first time in a floating zone mirror furnace under air or argon atmospheres. While CeNbO{sub 4} grown in air contained CeNbO{sub 4.08} as a minor impurity that compromised structural analysis, the argon atmosphere yielded a single phase crystal of monoclinic CeNbO{sub 4}, as confirmed by selected area electron diffraction, powder and single crystal X-ray diffraction. The structure was determined in the standard space group setting C12/c1 (No. 15), rather than the commonly adopted I12/a1. AC impedance spectroscopy conducted under argon found that stoichiometric CeNbO{sub 4} single crystals showed lower conductivity compared to CeNbO{sub 4+δ} confirming interstitial oxygen can penetrate through fergusonite and is responsible for the higher conductivity associated with these oxides. - Graphical abstract: Large fergusonite-type CeNbO{sub 4} crystals were prepared for the first time in a floating zone mirror furnace. Crystal growth in an argon atmosphere yielded a single phase monoclinic CeNbO4, as confirmed by selected area electron diffraction, powder and single crystal X-ray diffraction. The structure was determined in the standard space group setting C12/c1 (No. 15), rather than the commonly adopted I12/a1. AC impedancemore » spectroscopy found CeNbO{sub 4} single crystals showed lower conductivity compared to CeNbO{sub 4+δ} confirming interstitial oxygen can penetrate through fergusonite and is responsible for the higher conductivity associated with these oxides. Highlights: • Preparation of single crystals of CeNbO{sub 4} using a floating zone mirror furnace. • Correction to the crystal symmetry of the monoclinic form of CeNbO{sub 4}. • Report the conductivity of a single crystal of CeNbO{sub 4}.« less
Authors:
 [1] ; ; ; ;  [2] ;  [3] ;  [1] ;  [2] ;  [2]
  1. Department of Materials, Imperial College London, Prince Consort Road, London, SW7 2BP (United Kingdom)
  2. School of Materials Science and Engineering, 50 Nanyang Avenue, Nanyang Technological University, 639798 (Singapore)
  3. Chemical Crystallography Laboratory, Department of Chemistry, Imperial College London, Exhibition Road, London, SW7 2AZ (United Kingdom)
Publication Date:
OSTI Identifier:
22274051
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 204; Other Information: Copyright (c) 2013 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; ARGON; CRYSTAL GROWTH; ELECTROLYTES; ELECTRON DIFFRACTION; IONIC CONDUCTIVITY; MONOCLINIC LATTICES; MONOCRYSTALS; OXIDES; POWDERS; SOLID OXIDE FUEL CELLS; SPACE GROUPS; SPECTROSCOPY; X-RAY DIFFRACTION