Isotopic shifts of the unit cell constants of the α and β tri-hydrides of uranium: UH3, UD3, UT3

Johnson, Q.; Biel, T.J.; Leider, H.R.

doi:10.1016/0022-3115(76)90171-9

Cited by 12 publications

(5 citation statements)

References 6 publications

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“…Since β-UH 3 is the experimental stable phase, we mainly study its properties below. The measurement on the effect of isotopic substitution on the lattice constants and atomic positions of uranium hydride [20] found no changes in crystal structure, only with a slight decrease of the lattice constants when hydrogen isotopic mass increases, as listed in Table 1. Apparently, the calculated density reveals tiny differences among β-UH 3 , β-UD 3 and β-UT 3 .…”

Section: Resultsmentioning

confidence: 96%

“…On the other hand, the hydrogen isotopic effect of uranium hydride which is widely used to store and separate hydrogen isotope attracts extensive attention. Despite of the small isotopic shifts on the unit cell constants [12,19,20,21], the hydrogen isotopic effects on magnetic and thermodynamic properties of uranium hydride are comparatively remarkable. As uranium hydride is observed to be ferromagnetic, the Curie temperature of β-UH 3 differs from that of β-UD 3 [22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

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Hydrogen Isotopic Effects of Uranium Hydrides: First-Principles Calculations

2015

MSF

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In this paper, we study the ground-state and lattice dynamical properties of β-UH--3by means of the first-principles density functional theory within the local spin-density approximation (LSDA)+Uformulism. The lattice constants and electronic structure are correctly described by taking into account the strong on-site Coulomb repulsion among the 5felectrons localized on uranium atoms. Good agreement with experiments is achieved by tuning the effective Hubbard parameter at around 4 eV. The phonon band structure confirms the dynamical stability of β-UH--3, and the Raman-active modes are consistent with Raman spectrum measurements. The substitution of the deuterium (tritium) atom for hydrogen atom makes significant variations in the typical frequency of Raman-active modes. It is found that the Raman-active mode frequency is approximately inversely proportional to the square root of the hydrogen isotope mass. We conclude that Raman spectrum provides a powerful method for detecting hydrogen isotopic effects.

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Section: Resultsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Hydrogen Isotopic Effects of Uranium Hydrides: First-Principles Calculations

2015

MSF

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“…% > 75 for temperatu least up to 1100 °C. The crystal structure of UT 3 hydride is cubic, with a lattice constant of a=6.625±0.003 Å at room temperature [8]. This suggests a rather large volume expansion compared with the orthorhombic crystal structure of pure uranium metal at room temperature with lattice constants a=2.854 Å, b=5.870 Å, and c=4.955 Å.…”

Section: Phase Diagram and P-c-t Curvesmentioning

confidence: 95%

Uranium for hydrogen storage applications : a materials science perspective.

Shugard¹,

Tewell²,

Cowgill³

et al. 2010

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“…Uranium hydride has two kinds of crystal cubic structures corresponding to the low-temperature (far below room temperature, a-UH 3 ) and the high-temperature (b-UH 3 , space group Pm3n) phases. The lattice constants of b-UH 3 and b-UT 3 equal 6.6444 ± 0.0008 Å, and 6.625 ± 0.003 Å, respectively [12]. So, from the standpoint of radiation protection, the XRD analysis of fresh UT 3 is not necessary.…”

Section: Xrd Analysis Of Uranium Tritidementioning

confidence: 99%