Structural modifications of dodecatungstophosphoric acid hexahydrate induced by temperature in the 10–358 K range. In situ high-resolution neutron powder diffraction investigation

A. Kremenovic (1, 2) , Anne Spasojevic - de Biré (1) , F. Bouree (3) , Ph. Colomban (4) , R. Dimitrijević (2) , M. Davidović (5) , U.B. Mioč (6)

1 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides
2 Department of Crystallography [University of Belgrade]
3 LLB - UMR 12 - Laboratoire Léon Brillouin
4 LADIR - Laboratoire de Dynamique Interactions et Réactivité
5 Vinča Institute of Nuclear Sciences
6 Faculty of Physical Chemistry

Dodecatungstophosphoric acid hexahydrate H3PW12O40·6H2O crystal structure has been investigated by neutron powder diffraction (NPD) at different temperatures in the 10–358 K range. A nonconvergent reversible phase transition has been noticed at about 320 K. This transition is associated with a change in dynamic equilibrium of hydrate species and partial reduction/oxidation (redox) W6+↔W5+. Expressive structure changes lie in the PO bonding inside Keggin's anion and the H5O2+ conformational angle.

Domaines: Sciences de l'ingénieur [physics]; Matériaux

A. Kremenovic, Anne Spasojevic - de Biré, F. Bouree, Ph. Colomban, R. Dimitrijević, et al.. Structural modifications of dodecatungstophosphoric acid hexahydrate induced by temperature in the 10–358 K range. In situ high-resolution neutron powder diffraction investigation. Solid State Ionics, 2002, 150 (3-4), pp.431-442. ⟨10.1016/S0167-2738(02)00419-8⟩. ⟨hal-02298723⟩