Microscopic Characterization of Uranium Nitrides Synthesized by Oxidative Ammonolysis of Uranium Tetrafluoride, Chemistry of Materials

Authors

G. W. Chinthaka Silva, University of Nevada, Las VegasFollow
Charles B. Yeamans, University of CaliforniaFollow
Longzhou Ma, University of Nevada, Las VegasFollow
Gary S. Cerefice, University of Nevada, Las VegasFollow
Kenneth Czerwinski, University of Nevada, Las VegasFollow
Alfred P. Sattelberger, University of NevadaFollow

Document Type

Article

Publication Date

2008

Publication Title

Chemistry of Materials

Publisher

American Chemical Society

Volume

20

Issue

9

First page number:

3076

Last page number:

3084

Abstract

The oxidative ammonolysis route was used to synthesize three uranium nitrides, UN₂, U₂N₃, and UN, using UF₄ as the starting material. Powder XRD analysis showed the UN₂ and U₂N₃ products to contain less than 1.0 wt % uranium oxides. UO₂ level was identified to be 5.0 (0) wt % in the UN product as it is made, but this level increases upon exposure to air. The morphology of these nitrides was studied with SEM, while the microstructures of UN₂ and U₂N₃ were investigated by TEM techniques for the first time. An explicit microstructural characterization of UN is also presented. These characterizations showed that UN has a long-range order in its structure and bulk of the UO₂ impurities present on the UN microparticle surface, likely originating from minute oxygen impurities in the inert atmosphere cover gas and/or diffusion through the quartz reactor tube at high temperatures. Surface area measurements demonstrated a 10-fold increase in surface area during the ammonolysis step, from 0.03 to 0.26 m²/g, and minimal change during the denitriding step.

Keywords

Ammonia; Nitrides; Solvolysis; Transmission electron microscopes; Uranium ores; Uranium oxides

Disciplines

Analytical Chemistry | Chemistry | Other Chemistry | Radiochemistry

Language

English

Permissions

Use Find in Your Library, contact the author, or use interlibrary loan to garner a copy of the article. Publisher copyright policy allows author to archive post-print (author’s final manuscript). When post-print is available or publisher policy changes, the article will be deposited

Repository Citation

Silva, G. W., Yeamans, C. B., Ma, L., Cerefice, G. S., Czerwinski, K., Sattelberger, A. P. (2008). Microscopic Characterization of Uranium Nitrides Synthesized by Oxidative Ammonolysis of Uranium Tetrafluoride, Chemistry of Materials. Chemistry of Materials, 20(9), 3076-3084.
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