Auger electron spectroscopic study of the surface oxidation of uranium–niobium alloy {U–6wt.% Nb} in a UHV environment containing primarily H2, H2O and CO

Younes, C.M.; Allen, G. C.; Embong, Zaidi

doi:10.1016/j.susc.2007.05.032

Cited by 18 publications

(12 citation statements)

References 24 publications

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“…Oxygen diffusion into the bulk metal has been observed for thorium 51 and uranium 52 and was previously suggested for erbium. 7 Evidence for this mechanism is supported using ToF-SIMS and quantitative LEIS depth profiles on activated and untreated erbium films, Figs.…”

Section: F Depth Profilingmentioning

confidence: 57%

Activation of erbium films for hydrogen storage

Brumbach

Ohlhausen

Zavadil

et al. 2011

Journal of Applied Physics

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Hydriding of metals can be routinely performed at high temperature in a rich hydrogen atmosphere. Prior to the hydrogen loading process, a thermal activation procedure is required to promote facile hydrogen sorption into the metal. Despite the wide spread utilization of this activation procedure, little is known about the chemical and electronic changes that occur during activation and how this thermal pretreatment leads to increased rates of hydrogen uptake. This study utilized variable kinetic energy X-ray photoelectron spectroscopy to interrogate the changes during in situ thermal annealing of erbium films, with results confirmed by time-of-flight secondary ion mass spectrometry and low energy ion scattering. Activation can be identified by a large increase in photoemission between the valence band edge and the Fermi level and appears to occur over a two stage process. The first stage involves desorption of contaminants and recrystallization of the oxide, initially impeding hydrogen loading. Further heating overcomes the first stage and leads to degradation of the passive surface oxide leading to a bulk film more accessible for hydrogen loading.

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Section: F Depth Profilingmentioning

confidence: 57%

Activation of erbium films for hydrogen storage

Brumbach

Ohlhausen

Zavadil

et al. 2011

Journal of Applied Physics

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“…While nitrogen will not react with uranium at room temperature, the corrosion of uranium in air is often simplified to reaction of uranium with oxygen. With the facilities of vacuum analytical tools, large amount of work was devoted to surface reaction of uranium with oxygen, and the oxidation mechanism of pure uranium has been studied clearly [19,28,[31][32][33][34][35][36][37][38][39]. Because of the dependence of the oxidation products on oxygen partial pressure, surface states and temperature, at least 16 oxides were recognized as the principal products of uranium metal corrosion under different experimental conditions [1,35,36].…”

Section: Reaction Of Uranium Metal Surface With Omentioning

confidence: 99%

“…oxidation-resistance, and mechanical properties, but the diversity of alloying elements enlarges the uranium-base alloy systems, which scatters the researches, such as described for U-Nb [28], U-Nb-Zr [87], U-Cr [16,18], U-Mo [46], etc. In literature, the majority is concentrated on physical metallurgy and mechanical properties of uranium alloys; only limited oxidation studies were recorded.…”

Section: Reaction Of U-nb Alloy Under Different Conditionsmentioning

confidence: 99%

“…Owing to its good performance in applications, the U-Nb system, which was not widely studied, was chosen for our exploration, and we are more interested in oxidation and hydrogenation of U-Nb alloy [27,70,[88][89][90]. Few works related to oxidation of U-Nb alloys have been carried out [28,89]. The addition of alloying Nb complicates the microstructure, and this makes the whole oxidation kinetics more confused.…”

Section: Reaction Of U-nb Alloy Under Different Conditionsmentioning

confidence: 99%

“…Because of comparable importance of oxidation and hydrogenation of uranium in the field of surface chemistry, studies on both oxidation and hydrogenation of uranium under various conditions were taken into account for an understanding of the corrosion mechanism [20][21][22][23][24][25][26][27][28]. For pure uranium, good consistency has been found between international results and ours, and more attention has been paid to attempts on application of non-traditional techniques in this field [22,23].…”

Section: Introductionmentioning

confidence: 99%

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Recent advances in study of uranium surface chemistry in China

2014

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Uranium is very important in nuclear energy industry; however, uranium and its alloys corrode seriously in various atmospheres because of their chemical reactivities. In China, continuous investigations focused on surface chemistry have been carried out for a thorough understanding of uranium in order to provide technical support for its engineering applications. Oxidation kinetics of uranium and its alloys in oxidizing atmospheres are in good agreement with those in the literature. In addition to the traditional techniques, non-traditional methods have been applied for oxidation kinetics of uranium, and it has been verified that spectroscopic ellipsometry and X-ray diffraction are effective and nondestructive tools for in situ kinetic studies. The inhibition efficiency of oxidizing gas impurities on uranium hydrogenation is found to follow the order CO 2 > CO > O 2 , and the broadening of XPS shoulders with temperature in depth profile of hydrogenated uranium surface is discussed, which is not mentioned in the literature. Significant progress on surface chemistry of alloyed uranium (U-Nb and U-Ti) in hydrogen atmosphere is reported, and it is revealed that the hydrating nucleation and subsequent growth of alloyed uranium are closely connected with the surface states, underlying metal matrix, and it is microstructure-dependent. In this review, the recent advances in uranium surface chemistry in China, published so far mostly in Chinese language, are briefly summarized. Suggestions for further study are made.

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Gas Releasing Mechanism of LLM‐105 Using Two‐Dimensional Correlation Infrared Spectroscopy

Xiao

Sui

Qian

et al. 2019

Propellants Explo Pyrotec

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In this paper, a sealed in-situ reaction system and infrared spectroscopy (IR) were used to study the gas releasing mechanism of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) at different temperatures. Three characteristic stages of LLM-105 during the heating process to 400°C were detected by the moving-window two-dimensional correlation spectroscopy (MW2D). Two-dimensional correlation infrared spectroscopy (2DCOS) was employed to examine changes of gas concentration in the sealed system at each stage. We found that in the first stage, LLM-105 first released H 2 O and NH 3 . In the second stage, the decomposition is intensified, the explosive molecule first undergoes the decomposition reaction of releasing H 2 O, and CO 2 , subsequently chemical reaction producing several nitrogen gases, such as NO, N 2 O, HCN, NO 2 and NH 3 . In the third stage, the decomposition process mainly releases CO 2 and NH 3 , and the concentrations of HCN and NO 2 decreased gradually. 2DCOS proven to be a very sensitive method for detecting thermal decomposition mechanisms and monitoring gas changes in sealed system.

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Auger electron spectroscopic study of the surface oxidation of uranium–niobium alloy {U–6wt.% Nb} in a UHV environment containing primarily H2, H2O and CO

Cited by 18 publications

References 24 publications

Activation of erbium films for hydrogen storage

Activation of erbium films for hydrogen storage

Recent advances in study of uranium surface chemistry in China

Gas Releasing Mechanism of LLM‐105 Using Two‐Dimensional Correlation Infrared Spectroscopy

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