The Structures of the Carbides, Nitrides and Oxides of Uranium<sup>1</sup>

Rundle, R. E.; Baenziger, N. C.; Wilson, Angela; McDonald, R. A.

doi:10.1021/ja01181a029

Cited by 315 publications

(125 citation statements)

References 0 publications

Supporting

Mentioning

108

Contrasting

Order By: Relevance

“…( 1). The C/U atom ratios at the carbon saturated UC, phase boundary were found to be 1.912 at 1,6Oo"C, 1.898 at 1,7Oo"C, 1.914 at 1,83O"C, and 1.923 a t 2,20O"C. These results agree well with those by chemical analysis. The U-rich UC, phase boundary could not be found from the lattice parameter.…”

Section: } (1)supporting

confidence: 86%

See 1 more Smart Citation

Studies on the Uranium Dicarbide Phase

Tagawa

Fujii

Sasaki

1971

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

The lattice parameters of UC, are examined as a function of carbon content and annealing conditions on sintered carbides between UC1.5 and UC,., (7.0 to 10.0% of carbon). The values of UC, obtained under equilibrium state are around a0=3.5253 and c0=5.9994 A. The lattice parameter measurements were made also on UC, obtained under non-equilibrium conditions by arc-melting and carbothermic reaction of UO,. The lattice parameters were appreciably smaller than on the specimens obtained under equilibrium. With annealing, both the lattice parameter and the combined carbon content showed a tendency to increase.

show abstract

Section: } (1)supporting

confidence: 86%

“…3, would indicate that the carbothermic reaction of UO, proceeds in two steps: (1) a dicarbide structure containing many vacancies is formed by the reaction, and (2) the deficient carbon sites are filled by C atoms.…”

Section: Time Hrmentioning

confidence: 99%

Studies on the Uranium Dicarbide Phase

Tagawa

Fujii

Sasaki

1971

Journal of Nuclear Science and Technology

View full text Add to dashboard Cite

show abstract

“…The calculated lattice constant of UN 2 is 5.276 Å (experimental value 5.31 [16]) and the bulk modulus calculated by using the third-order Birch-Murnaghan equation of states (EOS) [17] is 250 GPA in the order of other theoretical values (252 [15], from 235.8 to 264.6 Gpa [18]). Nevertheless, the lattice constant was somewhat smaller than the experimental value.…”

Section: Calculation Methods and Definitionsmentioning

confidence: 76%

Adsorption and diffusion of oxygen atom on UN2(100) surface and subsurface: a density functional theory study (DFT and DFT + U)

et al. 2014

View full text Add to dashboard Cite

In the present work, adsorption and diffusion of oxygen (O) atom on uranium dinitride (UN 2 ) is studied to map out the preferential UN 2 (100) surface site. The first principle method based on density functional theory (DFT) within the generalized gradient approximation PBE and the covariant version energy functional PBE ? U correction were used. The supercell approach and a coverage dependence of the adsorption structures and energetic were studied in detail for several monolayers' (ML) range. Potential energy surfaces (PES) corresponding to the interaction between O atom and UN 2 (100) on surface and subsurface for several sites and layers (Top U and Top N slabs) were calculated and favorable sites were identified with their maxima energy stable positions, which were then analyzed. For all positions, the PES show the same system behavior, when the O atom is sufficiently far from the UN 2 surface, and the energy of the system tends to the sum of free UN 2 slab and free oxygen atom energies. In return, when the distances decrease, strong interactions appear with presence of important potential wells. Calculation results showed that favored on-surface site for O atom adsorption were found to be near the bridge one for the UN (Top U slab) corresponding to five layers, uranium terminated and top one for (Top N slab) corresponding to six layers nitrogen terminated, the maximum system energy is situated at a position of about 1.2 and 1.5 Å from the surface for the two layers types calculations respectively. For subsurface results, only Top N presents a favorable incorporation site at the hollow position and the penetration of O atom is about -0.5 Å from the surface. DFT ? U study confirms all the results obtained by DFT calculations; that is, the maxima site positions for oxygen atom and the adhesion energy values per atom are of the same order of magnitudes. The adsorption energy per oxygen atom and the mean distance from the top surface gradually decrease with the coverage of O atoms for both on-surface cases, Top U and Top N slabs, with oxygen occupying the favorable site. For the Top N slab hollow site, the incorporation of oxygen through the surface becomes effective from a coverage of 3/8 ML with an encrustation of about -0.3 Å .

show abstract

“…The resul ts obtained in the preSCl1.t study are given in table 6. The data indicate that DC en ters into a solid-state reaction with as much as 27 mole percent of DZC3 (13.5 mole percent of DC2) , to yield a single-phase region of DC solid solutions.…”

Section: Uc-b Ezcmentioning

confidence: 94%

An x-ray study of the system uranium monocarbide-uranium dicarbide-beryllium carbide

Burdick¹,

Parker²,

Roth³

et al. 1955

J. RES. NATL. BUR. STAN.

View full text Add to dashboard Cite

Mixed car bide preparations within t he system uranium m onocarbide-uranium dicarbideberyllium carbid e were investigated after heating and quenching. X-ray diffraction methods were used to identify the phases found and to determine the degree of interaction. Carbide alloys were studied after treatments at 1,700 0 and 1,900 0 C, and a co nstitutional diagram for the 1,700 0 C level is presented. No ternary compounds we re identified within the system. The limit of solubility of beryllium carbide in uranium monocarbide at 1,700 0 and 1,900 0 C was found to be 20 mole percent and 40 mole percent, respectively. Lattice parameters based on X-ray patterns in the back-reflection region failed to indicate any other interactions, but evidence is presented to ind icate some solid solution among the uranium carbides without lattice parameter change. The room-temperatlll'e stability of uranium sesquicarbide (U2C,), which has been reported by other investigators, was verified. X-ray diffraction data were obtained for this cubic compound, using CuKa radiation.

show abstract

The Structures of the Carbides, Nitrides and Oxides of Uranium¹

Abstract: Structures of Carbides, Nitrides and Oxides of Uranium 99 passed through the reactor at 235°. The effluent gaseous products of the reaction were found to be as follows Propylene Per cent.

Cited by 315 publications

References 0 publications

Studies on the Uranium Dicarbide Phase

Studies on the Uranium Dicarbide Phase

Adsorption and diffusion of oxygen atom on UN2(100) surface and subsurface: a density functional theory study (DFT and DFT + U)

An x-ray study of the system uranium monocarbide-uranium dicarbide-beryllium carbide

Contact Info

Product

Resources

About

The Structures of the Carbides, Nitrides and Oxides of Uranium1

Abstract: Structures of Carbides, Nitrides and Oxides of Uranium 99 passed through the reactor at 235°. The effluent gaseous products of the reaction were found to be as follows Propylene Per cent.

Cited by 315 publications

References 0 publications

Studies on the Uranium Dicarbide Phase

Studies on the Uranium Dicarbide Phase

Adsorption and diffusion of oxygen atom on UN2(100) surface and subsurface: a density functional theory study (DFT and DFT + U)

An x-ray study of the system uranium monocarbide-uranium dicarbide-beryllium carbide

Contact Info

Product

Resources

About

The Structures of the Carbides, Nitrides and Oxides of Uranium¹