HAL : in2p3-00107087, version 1
 DOI : 10.1021/ic060964c
 Inorganic Chemistry 45 (2006) 8408 -8413
 Neutron Diffraction Studies of U$_4$O$_9$: Comparison with EXAFS Results
 (2006)
 Conradson et al.1 have analyzed X-ray absorption fine-structure spectra of the UO$_2$-U$_4$O$_9$ system and concluded that oxygen atoms are incorporated in U$_4$O$_9$ as oxo groups with U-O distances in the range 1.72-1.76 Å. They also found that the uranium sublattice consists of an ordered portion and an additional 'spectroscopically silent' glassy portion. We have carried out studies of powdered U$_4$O$_9$ by neutron diffraction which contradict these conclusions from EXAFS measurements. Our analysis shows that there are no U-O bonds shorter than 2.2 Å and that U4O9 is crystallographically ordered with no evidence of a glassy structure.
 Thème(s) : Physique/Physique/Chimie-PhysiqueChimie/Chimie inorganique
 in2p3-00107087, version 1 http://hal.in2p3.fr/in2p3-00107087 oai:hal.in2p3.fr:in2p3-00107087 Contributeur : Dominique Girod <> Soumis le : Mardi 17 Octobre 2006, 13:37:53 Dernière modification le : Mardi 17 Octobre 2006, 14:34:52