$Pb_2F_eR_eO_6$: new defect pyrochlore oxide with a geometrically frustrated Fe/Re sublattice

Ramesha, K and Sebastian, L and Eichhorn, B and Gopalakrishnan, J (2003) $Pb_2F_eR_eO_6$: new defect pyrochlore oxide with a geometrically frustrated Fe/Re sublattice. In: Journal of Materials Chemistry, 13 (8). pp. 2011-2014.

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Abstract

Nominal $Pb_2F_eR_eO_6$ adopts a defect pyrochlore structure at ambient pressure unlike the other $A_2F_eR_eO_6$ (A = Ca, Sr, Ba). Rietveld refinement of the crystal structure of one of the compositions $Pb_2F_eR_eO_6._1$ from powder XRD data shows that the structure is cubic pyrochlore (a = 10.382 Å; space group: Fd3m) where oxygen vacancies occur at O2 (8b) sites. The divergence between the ZFC and FC magnetic susceptibility data and the non-Arrhenius resistivity behaviour of $Pb_2F_eR_eO_6_._1$ compositions are characteristic of the underlying geometrically frustrated Fe/Re cation sublattice in the pyrochlore structure.

Item Type:	Journal Article
Publication:	Journal of Materials Chemistry
Publisher:	Royal Society of Chemistry
Additional Information:	The copyright of this article belongs to Royal Society of Chemistry
Keywords:	Crystal lattices;Iron;Rhenium;Crystal structure;Magnetic susceptibility;Positive ions;X ray powder diffraction
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	23 Jun 2007
Last Modified:	19 Sep 2010 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/10132

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