Abstract

A series of uranium-containing gadolinium zirconate samples have been fabricated at 1450°C in oxidizing, inert and reducing atmospheres. X-ray diffraction, Raman spectroscopy and transmission electron microscopy have been utilized to confirm adoption of pyrochlore or defect fluorite structures. X-ray diffraction allowed determination of the bulk averaged structure while Raman spectroscopy and transmission electron microscopy were used to determine ordering at the microdomain scale. Diffuse reflectance, X-ray absorption near edge structure and X-ray photoelectron spectroscopies indicated a predominantly U6+ oxidation state for all the air-sintered samples, even when Ca2+ or A-site vacancies were incorporated to charge balance for U4+, a mixed U5+/U6+ oxidation state was found for samples sintered in argon, while a mixed U4+/U5+ oxidation state occurred for sintering under N2–3.5%H2. This demonstrates a degree of uranium oxidation state control through sintering conditions, and the potential of using gadolinium zirconates as host materials for uranium in nuclear waste applications.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.