The plutonium-oxygen phase diagram in the 25-900 °c range: Non-existence of the PuO1.515 phase

0Citations
Citations of this article
8Readers
Mendeley users who have this article in their library.

Abstract

Evaluation of data for phases formed in the Pu-O system at temperatures below 900 °C shows that the observed oxides are not at equilibrium. Results are consistent with coexistence of a hexagonal solid solution (hex-PuO1.5+z, 0 ≤ z ≤ 0.010) and a cubic phase (cub-PuO1.60) in equilibrium at 800 °C, but fail to confirm that the O/Pu ratio of the body-centered-cubic (bcc) oxide formed near the sesquioxide composition is 1.515 (1.52) or that bcc-PuO1.515 is formed by the peritectic reaction of hex-PuO1.510 with cub-PuO1.60. Stable Pu(IV)/Pu(III) ratios observed for products of the Pu-H2O reaction correspond to members of the PunO2n-2 homologous series, but a product is not formed at O/Pu = 1.515. Metastable bcc-PuO1.50 (n = 4) and stable hex-PuO1.5+z coexist below 285 °C, the point at which reversible eutectic decomposition of cubic PuO1.60 (n = 5) produces a non-equilibrium mixture of bcc-PuO1.50 and sub-stoichiometric dioxide (PuO2-y). Transformation of bcc-PuO1.50 to stable hex-PuO1.50 and reactions of the hexagonal oxide to form higher-composition cubic phases are kinetically hindered. An alternative diagram describing non-equilibrium chemical behavior of the Pu-O system is presented.

Cite

CITATION STYLE

APA

Haschke, J. M., Dinh, L. N., & McLean, W. (2015). The plutonium-oxygen phase diagram in the 25-900 °c range: Non-existence of the PuO1.515 phase. Journal of Nuclear Materials, 458, 275–280. https://doi.org/10.1016/j.jnucmat.2014.12.106

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free