First-principles comprehensive study of electronic and mechanical properties of novel uranium hydrides at different pressures

Liu, Min; Shi, Yongpeng; Li, Dianzhong; Mo, Wenlin; Fa, Tao; Bai, Bin; Wang, Xiaolin; Chen, Xing-Qiu

doi:10.1016/j.pnsc.2020.01.019

Cited by 8 publications

(8 citation statements)

References 46 publications

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“…This is distinct to the hydrogen dominant PDOS in Ca-H compounds, but analogous to the hydrogen-rich U-H compounds under high pressure [35]. Our calculation parameters for electronic structure followed [35] and [56]. In addition, [60] checked different effective on-site Coulombic repulsion U in Dudarev et al formulation [61], and pointed out that the influence of electronic correlation effect can be neglected in the hydrogen rich uranium hydrides.…”

Section: Electronic Structuresmentioning

confidence: 63%

“…There is almost no local charge between Ca and H, suggesting ionic bonding properties, while the ELF between U and H atoms indicates covalent bonding. The ELF results and COHP analysis indicate that the bonding properties of U-H in Ca-U-H resemble that in hydrogen rich uranium hydrides under high pressure [56].…”

Section: Electronic Structuresmentioning

confidence: 86%

“…The enthalpies of all the predicted compounds were larger than that of Ca plus U, suggesting that the Ca and U are immiscible above 100 GPa, and no compositions were on the Ca-U side of the ternary convex hull. The [55,56] pointed out that the zero-point energy (ZPE) has slight effects on the total energy and the overall phase stabilities in Ca-H and U-H under high pressure. Hence, we assume that it is safe to neglect the ZPE contribution in Ca-U-H calculations.…”

Section: Crystal Structures and Stabilitiesmentioning

confidence: 99%

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Superconducting ternary hydrides in Ca-U-H under high pressure

Wu,

Zhu,

Ding

et al. 2024

J. Phys.: Condens. Matter

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The research on hydrogen-rich ternary compounds attract tremendous attention for it paves new route to room-temperature superconductivity at lower pressures. Here, we study the crystal structures, electronic structures, and superconducting properties of the ternary Ca-U-H system, combining crystal structure predictions with ab-initio calculations under high pressure. We found four dynamically stable structures with hydrogen clathrate cages: CaUH12-Cmmm, CaUH12-Fd-3m, Ca2UH18-P-3m1, and CaU3H32-Pm-3m. Among them, the Ca2UH18-P-3m1 and CaU3H32-Pm-3m are likely to be synthesized below 1 megabar. The f electrons in U atoms make dominant contribution to the electronic density of states around the Fermi energy. The electron-phonon interaction calculations reveal that phonon softening in the mid-frequency region can enhance the electron-phonon coupling significantly. The Tc value of Ca2UH18-P-3m1 is estimated to be 57.5-65.8 K at 100 GPa. Our studies demonstrate that introducing actinides into alkaline-earth metal hydrides provides possibility in designing novel superconducting ternary hydrides.

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Section: Electronic Structuresmentioning

confidence: 63%

Section: Electronic Structuresmentioning

confidence: 86%

Section: Crystal Structures and Stabilitiesmentioning

confidence: 99%

See 1 more Smart Citation

Superconducting ternary hydrides in Ca-U-H under high pressure

Wu,

Zhu,

Ding

et al. 2024

J. Phys.: Condens. Matter

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“…All the calculations were performed with the Vienna Ab Initio Simulation Package (VASP) version 5.4.4. , The projector-augmented wave (PAW) method and Perdew–Burke–Ernzerhof (PBE) exchange-correlation functional were employed . Previous studies have demonstrated that GGA functionals could accurately describe the electronic structure of 5f metals including U and plutonium (Pu). − It has also been shown that DFT+ U calculations with Hubbard correction on 5f orbitals of U significantly overestimate the atomic volume of U metal and alloys . Therefore, we selected the PBE functional in this work.…”

Section: Methodsmentioning

confidence: 99%

Two-Dimensional Nanomaterials as Anticorrosion Surface Coatings for Uranium Metal: Physical Insights from First-Principles Theory

Guo

Wang

Batista

et al. 2021

ACS Appl. Nano Mater.

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Corrosion protection is vital to ensure the reliability and longterm durability of metal components. Coating surfaces with two-dimensional (2D) materials is an attractive approach due to the strength, impermeability, and chemical inertness of many materials in this family. The selection of the best 2D coating relies on a detailed understanding of the interaction between 2D nanomaterials and the metal. In this paper, we report the first theoretical study on the interfacial properties of the 2D nanomaterial and metal uranium (U) using first-principles calculations. We concentrated on the study of protecting U metal surfaces because this material is very susceptible to surface corrosion, and it is of tremendous technological importance to the nuclear industry. The corrosion of U is a great challenge for its safe handling, usage, and storage. Six representative 2D nanomaterials, including graphene, h-BN, MoS 2 , MoSe 2 , and oxygen passivated Ti 2 C layer (Ti 2 CO 2 and Ti 2 CO), were selected from the 2D material library. Our calculations show that the binding energies of graphene and h-BN are smaller than −1.0 J/m 2 on U surfaces. The binding energies of MoS 2 and MoSe 2 are in the range from −1.5 to −2.0 J/m 2 . Ti 2 C-based MXenes (Ti 2 CO 2 and Ti 2 CO) have binding energies larger than −2.0 J/m 2 . The binding strength is traced back to the charge transfer at the interface which also leads to the quenching of surface magnetic moments. It is found that the binding strength is not sensitive to the phase and surface orientation of U metal. Among all the studied 2D nanomaterials, Ti 2 C-based MXenes are the most suitable coatings for U. These physical insights into the interfacial properties can provide guidance to the selection of chemically inert and thermodynamically stable 2D anticorrosion coatings that can strongly bind to the surfaces of U and other materials.

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“…In addition, a series of results combining theory with experiment shows that actinide superhydrides with high hydrogen content can be formed with remarkable high T c superconductivity behavior at high pressures, such as in AcH 1-10 , 19 ThH 1-10 , [20][21][22][23] PaH 1-9 , 24 and UH 1-10 . [25][26][27][28][29] It remains, however, unclear how neptunium hydrides evolve under extended ranges of extreme compression.…”

Section: Introductionmentioning

confidence: 99%