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Andersson, David; Lezama, Juan S.; Uberuaga, Blas P.; Deo, Chaitanya; Conradson, Steven D.

doi:10.1103/physrevb.79.024110

Cited by 153 publications

(117 citation statements)

References 55 publications

(89 reference statements)

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“…Since the GGA+U and LDA+U give the similar description of the PDOS, here we only plot the GGA+U results. The orbital-resolved PDOS of the bulk PuO 2 at the ground state has been calculated and analyzed in detail by previous DFT+U [19,21,22,24] and hybrid DFT [9,16] studies, and those theoretical results of DOS are usually tested by comparing with the experimental photoelectron spectroscopy (PES) measurements [6,7].…”

Section: Resultsmentioning

confidence: 99%

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

Sun

Liu

Song

et al. 2012

Journal of Nuclear Materials

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The (111), (110), and (001) surfaces properties of PuO 2 are studied by using density-functional theory+U method. The total-energy static calculations determine the relative order of stability for low-index PuO 2 surfaces, namely, O-terminated (111) > (110) > defective (001) > polar (001).The effect of thickness is shown to modestly modulate the surface stability and chemical activity of the (110) (111) is found to be the most stable surface. Whereas under O-reducing conditions, the on-surface O-vacancy of C V = 1/9 is stable, and for high reducing conditions, the (111) surface with nearly one monolayer subsurface oxygen removed (C V = 8/9) becomes most stable.

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Section: Resultsmentioning

confidence: 99%

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

Sun

Liu

Song

et al. 2012

Journal of Nuclear Materials

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“…Previous papers considered mechanisms of xenon transfer and its interaction with uranium in UO 2+x (ref 9) theoretically, as well as the influence of defects 10,11 and pressure 12, 13 on the ionic composition of these oxides. Adsorption energies of water on differently oriented uranium dioxide planes were calculated.…”

Section: Introductionmentioning

confidence: 99%

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

et al. 2016

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XPS determination of the oxygen coefficient k O =2+x and ionic (U 4+ , U 5+ and U 6+ ) composition of oxides UO 2+x formed on the surfaces of differently oriented (hkl) planes of thin UO 2 films on LSAT (Al 10 La 3 O 51 Sr 14 Ta 7 ) and YSZ (yttria-stabilized zirconia) substrates was performed. The U 4f and O 1s core-electron peak intensities as well as the U 5f relative intensity before and after the 129 Xe 23+ and 238 U 31+ irradiations were employed. It was found that the presence of uranium dioxide film in air results in formation of oxide UO 2+x on the surface with mean oxygen coefficients k O in the range 2.07-2.11 on LSAT and 2.17-2.23 on YSZ substrates. These oxygen coefficients depend on the substrate and weakly on the crystallographic orientation.On the basis of the spectral parameters it was established that uranium dioxide films AP2,3 on the LSAT substrates have the smallest k O values, and from the XRD and EBSD results it follows that these samples have a regular monocrystalline structure. The XRD and EBSD results indicate that samples AP5-7 on the YSZ substrates have monocrystalline structure, however, they have the highest k O values. The observed difference in the k O values, probably, caused by the different nature of the substrates: the YSZ substrates provide 6.4% compressive strain, whereas (001) LSAT substrates result only in 0.03% tensile strain in the UO 2 films.129 Xe 23+ irradiation (92 MeV, 4.8 × 10 15 ions/cm 2 ) of uranium dioxide films on the LSAT substrates was shown to destroy both long range ordering and uranium close environment, which results in increase of uranium oxidation state and regrouping of oxygen ions in uranium close environment. 238 U 31+ (110 MeV, 5 × 10 10 , 5 × 10 11 , 5 × 10 12 ions/cm 2 ) irradiations of uranium dioxide films on the YSZ substrates were shown to form the lattice damage only with partial destruction of the long range ordering.3

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“…The effective modification of pure DFT by LDA/GGA+U formalisms has been confirmed widely in studies of PuO 2 [27][28][29][30][31][32][33][34][35], which have reported the AFM-insulator ground state of…”

Section: Introductionmentioning

confidence: 98%

The environmental dependence of redox energetics of PuO2 and α-Pu2O3: A quantitative solution from

et al. 2012

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We report a comprehensive density functional theory (DFT) + U study of the energetics of charged and neutral oxygen defects in both PuO 2 and α-Pu 2 O 3 , and present a quantitative determination of the equilibrium compositions of reduced PuO 2 (PuO 2−x ) as functions of environmental temperature and partial pressure of oxygen, which shows fairly agreement with corresponding high-temperature experiments. Under ambient conditions, the endothermic reduction of PuO 2 to α-Pu 2 O 3 is found to be facilitated by accompanying volume expansion of PuO 2−x and the possible migration of O-vacancy, whereas further reduction of α-Pu 2 O 3 is predicted to be much more difficult. In contrast to the endothermic oxidation of PuO 2 , the oxidation of α-Pu 2 O 3 is a stable exothermic process.

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Cooperativity among defect sites inAO2+xandA4O9

Cited by 153 publications

References 55 publications

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

The environmental dependence of redox energetics of PuO2 and α-Pu2O3: A quantitative solution from

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Cooperativity among defect sites inAO2+xandA4O9

Cited by 153 publications

References 55 publications

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

First-principles study of surface properties of PuO2: Effects of thickness and O-vacancy on surface stability and chemical activity

XPS Study of Ion Irradiated and Unirradiated UO2 Thin Films

The environmental dependence of redox energetics of PuO2 and α-Pu2O3: A quantitative solution from

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XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films