Oxide structure of air-passivated U-6Nb alloy thin films

JOURNAL OF NUCLEAR MATERIALS

卷:539

Article

Watkins, Erik B.¹  Kruk, Izabela¹  Majewski, Jaroslaw^2,3,4  Allred, David D.⁵ 

[1] Los Alamos Natl Lab, Mat Phys & Applicat Div, Los Alamos, NM 87545 USA

[2] Univ New Mexico, Dept Chem & Biol Engn, Albuquerque, NM 87131 USA

[3] Los Alamos Natl Lab, Theoret Biol & Biophys Div, Los Alamos, NM 87545 USA

[4] Natl Sci Fdn, Div Mol & Cellular Biosci, Alexandria, VA 22314 USA

[5] Brigham Young Univ Provo, Dept Phys & Astron, Provo, UT 84602 USA

关键词: Uranium-niobium alloys;    Corrosion;    Sputtered films;    X-ray diffraction;    Neutron reflectometry;   

DOI  :  10.1016/j.jnucmat.2020.152356

来源: Elsevier

【 摘 要 】

U-6Nb is a uranium alloy containing 6 wt% niobium that possesses high corrosion resistance. The structure and composition of the passivating oxide layer formed on air-aged U-6Nb, which gives the material its corrosion resistant properties, was characterized using surface scattering techniques. Stable oxide layers formed on the surface of a set of U-6Nb alloy thin films under ambient conditions were investigated using neutron reflectometry (NR), x-ray reflectometry (XRR) and grazing incidence x-ray diffraction (GIXD). The passivating oxide was composed of approximately 27% U, 5% Nb, and 68% O, primarily consisting of a thin niobium oxide layer (5.5 +/- 0.4 nm) separating a thicker UO2 layer (27.1 +/- 2.3 nm) from the underlying U-6Nb alloy. A critical density of enriched niobium oxide at the metal-oxide interface is hypothesized to limit oxygen diffusion and confer high corrosion resistance to the alloy. (C) 2020 Elsevier B.V. All rights reserved.

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