EELS Spectrum Imaging and Tomography Studies of Simulated Nuclear Waste Glasses

Conference · Sun Jul 01 00:00:00 EDT 2007

OSTI ID:21062402

Yang, Guang; Saghi, Zineb; Xu, Xiaojing; Hand, Russell; Moebus, Guenter ^[1]

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1. Engineering Materials, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD (United Kingdom)

Electron energy loss spectroscopy (EELS) fine structure is a powerful technique for analyzing oxidation levels of rare-earth oxides and coordination numbers in glasses and ceramics, especially for boron. To exploit the unique advantage of EELS over x-ray absorption spectroscopy (XAS)/x-ray absorption near edge structure (XANES), namely nm-scale spatial resolution, EELS spectrum imaging across precipitates in glasses has been employed to detect lateral changes of EELS fine structure. Alkali borosilicate (ABS) glasses doped with Cr{sub 2}O{sub 3}, CeO{sub 2} and ZrO{sub 2} or Fe{sub 2}O{sub 3} were melted to simulate high level radionuclide immobilization glasses. Precipitates with diameter in the range of {approx}20 nm to {approx}500 nm were found homogeneously distributed in the glasses. Ce valence was found to be mainly +3 in the glass matrix, and +4 in crystalline precipitates, while some amorphous particles show +3 as well. Another powerful TEM technique for the analysis of glass-nano-composites is electron tomography, as it is up to now the only technique for the three-dimensional reconstruction of nano-particles. A 3D reconstructed nuclear waste glass is presented in this paper by using a tilt series of ADF STEM images covering a glass fragment of {approx}3{mu}m field of view containing several tens of nano-particles distributed throughout its volume. (authors)

• Research Organization: Materials Research Society, 506 Keystone Drive, Warrendale, PA, 15086-7573 (United States)
• OSTI ID: 21062402
• Resource Relation: Conference: Symposium on Scientific Basis for Nuclear Waste Management, Boston - Massachusetts (United States), 27 Nov - 1 Dec 2006; Other Information: Country of input: France; 25 refs; Related Information: In: Proceedings of the symposium on Scientific Basis for Nuclear Waste Management XXX, by Dunn, Darrell [ed. Southwest Research Inst., San Antonio, Texas (United States)]; Poinssot, Christophe [ed. CEA-Saclay, 91191 Gif-sur-Yvette cedex (France)]; Begg, Bruce [ed. Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)], v. 985, 663 pages.
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTROSCOPY
BOROSILICATE GLASS
CERIUM OXIDES
CHROMIUM OXIDES
COMPOSITE MATERIALS
DOPED MATERIALS
ENERGY-LOSS SPECTROSCOPY
FINE STRUCTURE
IRON OXIDES
NANOSTRUCTURES
PRECIPITATION
RADIOACTIVE WASTES
TOMOGRAPHY
TRANSMISSION ELECTRON MICROSCOPY
X-RAY SPECTROSCOPY
ZIRCONIUM OXIDES