In:
Journal of Materials Research, Springer Science and Business Media LLC, Vol. 15, No. 9 ( 2000-09), p. 1972-1984
Abstract:
The local structure of iron and uranium ions in a series of iron phosphate glasses with the general composition (40 – x )Fe 2 O 3 – x UO 2 –60P 2 O 5 and (1– x–y )(40Fe 2 O 3 –60P 2 O 5 )– x UO 2– y (Na 2 O or CaO) was investigated using Fe K-edge and U L III -edge x-ray absorption fine structure spectroscopy. Replacing Fe 2 O 3 by UO 2 in the glass caused more distortion in the coordination environment of Fe(III) ions. Extended x-ray absorption fine structure fits revealed that the Fe–P bonds observed in the base glass also existed in all the waste-loaded glasses. X-ray absorption near-edge structure showed that the uranium ions were predominantly present as U(IV) in the glasses. Uranium ions were coordinated to approximately 8 ± 1 oxygen atoms and 2.5 ± 0.6 phosphorus atoms at an average distance of 2.47 ± 0.02 and 3.8 ± 0.02 Å, respectively. There were no Fe–U or U–Fe neighbors observed, indicating that uranium ions occupied voids in the glass away from the PO 4 units. These conclusions were supported by Mössbauer, x-ray photoelectron, and Raman spectroscopic data.
Type of Medium:
Online Resource
ISSN:
0884-2914
,
2044-5326
DOI:
10.1557/JMR.2000.0284
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2000
detail.hit.zdb_id:
54876-5
detail.hit.zdb_id:
2015297-8