s'authentifier
version française rss feed
HAL : in2p3-00185294, version 1

Fiche concise  Récupérer au format
Crystal structures of Th(OH)PO_4, U(OH)PO_4 and Th_2 O(PO_4)_2. Condensation mechanism of M^IV (OH)PO_4 (M = Th, U) into M_2 O(PO_4)_2
Dacheux N., Clavier N., Wallez G., Quarton M.
Dans Solid State Sciences - 1st International Symposium on Structure-Property Relationships in Solid State Materials, Bordeaux : - http://hal.in2p3.fr/in2p3-00185294
Physique/Physique/Chimie-Physique
Crystal structures of Th(OH)PO_4, U(OH)PO_4 and Th_2 O(PO_4)_2. Condensation mechanism of M^IV (OH)PO_4 (M = Th, U) into M_2 O(PO_4)_2
N. Dacheux1, N. Clavier1, G. Wallez2, M. Quarton2
1 :  IPNO - Institut de Physique Nucléaire d'Orsay
http://ipnweb.in2p3.fr
CNRS : UMR8608 – IN2P3 – Université Paris XI - Paris Sud
IPN - 15, rue Georges Clemenceau - 91406 ORSAY CEDEX
France
2 :  LCMCP (site Paris VI) - Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI)
http://www.labos.upmc.fr/lcmcp/
CNRS : UMR7574 – Collège de France – Université Pierre et Marie Curie (UPMC) - Paris VI – Ecole Nationale Supérieure de Chimie de Paris
4, Place Jussieu - Tour 54 - E.5 - couloir 54-55 75252 - Paris Cedex 05
France
Three new crystal structures, isotypic with β-Zr2O(PO4)2, have been resolved by the Rietveld method. All crystallize with an orthorhombic cell (S.G.: Cmca) with a = 7.1393(2) Å, b = 9.2641(2) Å, c = 12.5262(4) Å, V = 828.46(4) Å3 and Z = 8 for Th(OH)PO4; a = 7.0100(2) Å, b = 9.1200(2) Å, c = 12.3665(3) Å, V = 790.60(4) Å3 and Z = 8 for U(OH)PO4; a = 7.1691(3) Å, b = 9.2388(4) Å, c = 12.8204(7) Å, V = 849.15(7) Å3 and Z = 4 for Th2O(PO4)2. By heating, the M(OH)PO4 (M = Th, U) compounds condense topotactically into M2O(PO4)2, with a change of the environment of the tetravalent cation that lowers from 8 to 7 oxygen atoms. The lower stability of Th2O(PO4)2 compared to that of U2O(PO4)2 seems to result from this unusual environment for tetravalent thorium.

Communications avec actes
2007
Solid State Sciences
internationale
9
619-627
Elsevier

1st International Symposium on Structure-Property Relationships in Solid State Materials
Bordeaux
06/2006
N. Dacheux