Stoichiometry of UAl4

Tougait, Olivier; Noël, H.

doi:10.1016/j.intermet.2003.09.012

Cited by 67 publications

(35 citation statements)

References 8 publications

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“…The binding energy for the optimized Al 13 is 2.73 eV/atom, which is slightly larger than the previous GGA calculated values of 2.68 eV [28], 2.70 eV [29] and 2.66 eV [6]. The nearest-neighbor distances lie in the range of 2.772-2.852 Å , which is in good agreement the previously reported values 2.63-3.01 Å by Wang [6] and 2.71-3.12 Å by Rao [28], and comparable to the experiment distance of 2.864 Å [30] and 2.618-2.958 Å [31] in the bulk system.…”

Section: Resultssupporting

confidence: 92%

Density Functional Theory Studies on the Adsorption of NH2NO2 on Al13 Cluster

Zhao

et al. 2012

J Clust Sci

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Density functional theory method with full geometry optimization was used to study the adsorption of nitroamine (NH 2 NO 2 ) on Al 13 cluster. Both dissociative and nondissociative adsorption structures were predicted with different NH 2 NO 2 molecule orientations on Al 13 cluster surfaces. In dissociative chemisorption, the main decomposition products of NH 2 NO 2 are O atom(s) and NH 2 NO or NH 2 N species. The O atoms being ruptured from the N-O bond form strong Al-O bonds with the neighboring Al around the adsorbed sites. In addition, the species obtained as a result of O atom elimination remains bonded to the surface. The largest adsorption energy is -737.66 kJ/mol when the NH 2 NO 2 molecule decomposes into two O atoms and a NH 2 N fragment. For nondissociative adsorption, the seriously deformed nitroamine forms various N-O-Al bonding configurations with Al. The significant charge transfer occurs for all adsorption configurations. The most charge transfer is 2.068 e from the Al cluster surface to the fragments of the decomposed NH 2 NO 2 . The change of the electronic structures is obvious due to the adsorption or dissociation of NH 2 NO 2 molecule. Nitroamine readily oxidizes the aluminum surface of the Al 13 cluster.

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Section: Resultssupporting

confidence: 92%

Density Functional Theory Studies on the Adsorption of NH2NO2 on Al13 Cluster

Zhao

et al. 2012

J Clust Sci

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“…Single-crystal X-ray diffraction data were collected on a Nonius Kappa CCD diffractometer, using well-established procedures [11].…”

Section: Methodsmentioning

confidence: 99%

Phase relations in the U–Mo–Al ternary system

Noël

Tougait

Dubois

2009

Journal of Nuclear Materials

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“…The UAl 3 [32] has the AuCu 3 cubic (Pm3m) structure, the UAl 4 has the orthorhombic (Imma) structure, [33][34][35] the U 6 Mo 4 Al 43 [36] has the hexagonal (P6 3 /mcm) structure, and the UMo 2 Al 20 has the cubic (Fd3m) structure. [37] Zenou et al [38] reported that the U 0.9 Al 4 phase deviation from the expected UAl 4 stoichiometry is a result of vacancies at the U sites (e.g., 92 pct U-site occupation).…”

mentioning

confidence: 99%

Phase Constituents and Microstructure of Interaction Layer Formed in U-Mo Alloys vs Al Diffusion Couples Annealed at 873 K (600 °C)

Perez

Keiser

Sohn

2011

Metall Mater Trans A

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U-Mo dispersion and monolithic fuels are being developed to fulfill the requirements for research reactors, under the Reduced Enrichment for Research and Test Reactors program. In dispersion fuels, particles of U-Mo alloys are embedded in the Al-alloy matrix, while in monolithic fuels, U-Mo monoliths are roll bonded to the Al-alloy matrix. In this study, interdiffusion and microstructural development in the solid-to-solid diffusion couples, namely, U-15.7 at. pct Mo (7 wt pct Mo) vs pure Al, U-21.6 at. pct Mo (10 wt pct Mo) vs pure Al, and U-25.3 at. pct Mo (12 wt pct Mo) vs pure Al, annealed at 873 K (600°C) for 24 hours, were examined in detail. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron probe microanalysis (EPMA) were employed to examine the development of a very fine multiphase interaction layer with an approximately constant average composition of 80 at. pct Al. Extensive TEM was carried out to identify the constituent phases across the interaction layer based on selected area electron diffraction and convergent beam electron diffraction (CBED). The cubic-UAl 3 , orthorhombic-UAl 4 , hexagonal-U 6 Mo 4 Al 43 , and cubicUMo 2 Al 20 phases were identified within the interaction layer that included two-and three-phase layers. Residual stress from large differences in molar volume, evidenced by vertical cracks within the interaction layer, high Al mobility, Mo supersaturation, and partitioning toward equilibrium in the interdiffusion zone were employed to describe the complex microstructure and phase constituents observed. A mechanism by compositional modification of the Al alloy is explored to mitigate the development of the U 6 Mo 4 Al 43 phase, which exhibits poor irradiation behavior that includes void formation and swelling.

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Stoichiometry of UAl4

Cited by 67 publications

References 8 publications

Density Functional Theory Studies on the Adsorption of NH2NO2 on Al13 Cluster

Density Functional Theory Studies on the Adsorption of NH2NO2 on Al13 Cluster

Phase relations in the U–Mo–Al ternary system

Phase Constituents and Microstructure of Interaction Layer Formed in U-Mo Alloys vs Al Diffusion Couples Annealed at 873 K (600 °C)

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