A rare earth L-3-edge EXAFS and L-1-edge XANES study of Ce, Nd and Eu phosphate glasses and crystals in the composition range from metaphosphate to ultraphosphate

Mountjoy, G. and Cole, J.M. and Brennan, T. and Newport, R.J. and Saunders, G.A. and Wallidge, G.W. (2001) A rare earth L-3-edge EXAFS and L-1-edge XANES study of Ce, Nd and Eu phosphate glasses and crystals in the composition range from metaphosphate to ultraphosphate. Journal of Non-Crystalline Solids, 279 (1). pp. 20-27. ISSN 0022-3093.

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Official URL http://dx.doi.org/10.1016/S0022-3093(00)00406-3

Abstract

Rare earth (R) phosphate glasses, (R2O3)(x)(P2O5)(1-x), can be prepared with compositions in the range from ultra-phosphate,x = 0.17 (RP5O14), to metaphosphate, x = 0.25 (RP3O9), and it is important to know whether the R-O coordination changes significantly with composition. In rare earth phosphate crystals, the number of nearest neighbour oxygens changes from eight for ultraphosphate to six for metaphosphate. These R-O correlations are clearly distinguished in L-3-edge extended X-ray absorption spectroscopy (EXAFS) of NdP5O14 and EuP3O9 crystals. Samples of Ce (x = 0.197 and 0.235), Nd (x = 0.187) and Eu (x = 0.218) phosphate glasses all show the same EXAFS and L-1-edge X-ray absorption near edge structures (XANES) results. The results indicate an R-O coordination with six nearest neighbour oxygens, a similar level of static disorder to that in rare earth phosphate crystals and reduced centrosymmetry. There is no evidence for a change in R-O coordination with changing x. (C) 2001 Elsevier Science B.V. All rights reserved.

Item Type:	Article
Uncontrolled keywords:	ABSORPTION FINE-STRUCTURE; RAY; SPECTROSCOPY; DIFFRACTION; EDGES; XAS; PR
Subjects:	Q Science Q Science > QC Physics
Divisions:	Faculties > Science Technology and Medical Studies > School of Physical Sciences > Functional Materials Group
Depositing User:	Bob Newport
Date Deposited:	26 Jun 2008 17:08
Last Modified:	06 Sep 2011 00:06
Resource URI:	http://kar.kent.ac.uk/id/eprint/8212 (The current URI for this page, for reference purposes)

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