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Title: Crystal structures of orthorhombic, hexagonal, and cubic compounds of the Sm{sub (x)}Yb{sub (2−x)}TiO{sub 5} series

A series of single phase compounds with nominal stoichiometry Sm{sub (x)}Yb{sub (2−x)}TiO{sub 5} (x=2, 1.4, 1, 0.6, and 0) have been successfully fabricated to generate a range of crystal structures covering the most common polymorphs previously discovered in the Ln{sub 2}TiO{sub 5} series (Ln=lanthanides and yttrium). Four of the five samples have not been previously fabricated in bulk, single phase form so their crystal structures are refined and detailed using powder synchrotron and single crystal x-ray diffraction, neutron diffraction and transmission electron microscopy. Based on the phase information from diffraction data, there are four crystal structure types in this series; orthorhombic Pnma, hexagonal P6{sub 3}/mmc, cubic (pyrochlore-like) Fd-3m and cubic (fluorite-like) Fm-3m. The cubic materials show modulated structures with variation between long and short range ordering and the variety of diffraction techniques were used to describe these complex crystal structure types. - Graphical abstract: A high resolution image of the compound Sm{sub 0.6}Yb{sub 1.4}TiO{sub 5} showing contrast from lattice fringes and the corresponding fast Fourier transform (FFT) of the HREM image with pyrochlore related diffraction spots marked “P” and fluorite marked “F”. The crystal is oriented down the [1 1 0] zone axis based on the Fd-3m structure. The idealmore » crystal structure (no vacancies) of the cubic, pyrochlore-like (Sm{sub 0.6}Yb{sub 1.4}TiO{sub 5}). - Highlights: • First fabrication of bulk single-phase material with stoichiometry Sm{sub 2}TiO{sub 5}. • Systematic study of crystal structure types within Ln{sub 2}TiO{sub 5} series (Ln=lanthanides). • A novel technique using IFFT of HREM images to study cubic structures.« less
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [4] ;  [5] ;  [1] ;  [6] ;  [7]
  1. Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)
  2. (Australia)
  3. School of Chemistry, The University of New South Wales, Sydney, NSW 2052 (Australia)
  4. School of Chemistry, The University of Sydney, Sydney, NSW 2006 (Australia)
  5. Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)
  6. Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai, NSW 2234 (Australia)
  7. Australian Centre for Microscopy and Microanalysis, The University of Sydney, NSW 2006 (Australia)
Publication Date:
OSTI Identifier:
22334219
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 213; 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; FLUORITE; FOURIER TRANSFORMATION; HCP LATTICES; MONOCRYSTALS; NEUTRON DIFFRACTION; ORTHORHOMBIC LATTICES; PYROCHLORE; RARE EARTHS; TITANIUM OXIDES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION