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Title: LnSrScO4 (Ln=La, Ce, Pr, Nd and Sm) systems and structure correlations for A {sub 2} BO{sub 4} (K{sub 2}NiF{sub 4}) structure types

Abstract

The compounds LnSrScO{sub 4}, where Ln=La, Ce, Pr, Nd and Sm, have been synthesized. Rietveld profile analysis of powder X-ray diffraction data collected at room temperature reveal that the compounds possess a modified K{sub 2}NiF{sub 4}-type structure with orthorhombic cell symmetry formed by tilting of the ScO{sub 6} octahedra. Variable temperature (25-1200 deg. C) powder X-ray diffraction data show that at the highest temperatures the structures of LaSrScO{sub 4} and PrSrScO{sub 4} transform to the regular tetragonal K{sub 2}NiF{sub 4}-structure type but the degree of orthorhombicity (c/a) in the unit cells initially increases on heating for all materials, reaching a maximum near 300 deg. C. This structural behavior is analyzed in terms of relative ionic radii of the various lanthanides and scandium. A general structural model based on tolerance factors has been developed for the family of materials A {sub 2} BO{sub 4} with various A and B cation sizes. - Graphical abstract: Tilting of the octahedra in K{sub 2}NiF{sub 4} structure type oxides (A {sub 2} BO{sub 4}) may be controlled by the A-type cation size and by temperature.

Authors:
 [1];  [1];  [2]
  1. School of Chemistry, University of Southampton, University Road, Highfield, Southampton SO17 1BJ (United Kingdom)
  2. School of Chemistry, University of Southampton, University Road, Highfield, Southampton SO17 1BJ (United Kingdom), E-mail: mtw@soton.ac.uk
Publication Date:
OSTI Identifier:
21015657
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.2006.10.023; PII: S0022-4596(06)00569-X; 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; BORATES; CERIUM COMPOUNDS; LANTHANUM COMPOUNDS; NEODYMIUM COMPOUNDS; ORTHORHOMBIC LATTICES; OXIDES; PHASE TRANSFORMATIONS; PRASEODYMIUM COMPOUNDS; SAMARIUM COMPOUNDS; SCANDIUM COMPOUNDS; STRONTIUM COMPOUNDS; STRUCTURAL MODELS; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TEMPERATURE RANGE 1000-4000 K; X-RAY DIFFRACTION

Citation Formats

Patel, Rina, Simon, Charles, and Weller, Mark T. LnSrScO4 (Ln=La, Ce, Pr, Nd and Sm) systems and structure correlations for A {sub 2} BO{sub 4} (K{sub 2}NiF{sub 4}) structure types. United States: N. p., 2007. Web. doi:10.1016/j.jssc.2006.10.023.
Patel, Rina, Simon, Charles, & Weller, Mark T. LnSrScO4 (Ln=La, Ce, Pr, Nd and Sm) systems and structure correlations for A {sub 2} BO{sub 4} (K{sub 2}NiF{sub 4}) structure types. United States. doi:10.1016/j.jssc.2006.10.023.
Patel, Rina, Simon, Charles, and Weller, Mark T. Mon . "LnSrScO4 (Ln=La, Ce, Pr, Nd and Sm) systems and structure correlations for A {sub 2} BO{sub 4} (K{sub 2}NiF{sub 4}) structure types". United States. doi:10.1016/j.jssc.2006.10.023.
@article{osti_21015657,
title = {LnSrScO4 (Ln=La, Ce, Pr, Nd and Sm) systems and structure correlations for A {sub 2} BO{sub 4} (K{sub 2}NiF{sub 4}) structure types},
author = {Patel, Rina and Simon, Charles and Weller, Mark T.},
abstractNote = {The compounds LnSrScO{sub 4}, where Ln=La, Ce, Pr, Nd and Sm, have been synthesized. Rietveld profile analysis of powder X-ray diffraction data collected at room temperature reveal that the compounds possess a modified K{sub 2}NiF{sub 4}-type structure with orthorhombic cell symmetry formed by tilting of the ScO{sub 6} octahedra. Variable temperature (25-1200 deg. C) powder X-ray diffraction data show that at the highest temperatures the structures of LaSrScO{sub 4} and PrSrScO{sub 4} transform to the regular tetragonal K{sub 2}NiF{sub 4}-structure type but the degree of orthorhombicity (c/a) in the unit cells initially increases on heating for all materials, reaching a maximum near 300 deg. C. This structural behavior is analyzed in terms of relative ionic radii of the various lanthanides and scandium. A general structural model based on tolerance factors has been developed for the family of materials A {sub 2} BO{sub 4} with various A and B cation sizes. - Graphical abstract: Tilting of the octahedra in K{sub 2}NiF{sub 4} structure type oxides (A {sub 2} BO{sub 4}) may be controlled by the A-type cation size and by temperature.},
doi = {10.1016/j.jssc.2006.10.023},
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}
}