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Related papers: Structural and phase evolution in U$_3$Si$_2$ duri…

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The heavy fermion intermetallic compound URu2Si2 exhibits a "hidden-order" phase below the temperature of 17.5 K, which supports both anomalous metallic behavior and unconventional superconductivity. While these individual phenomena have…

High levels of deuterium fractionation of $\rm N_2H^+$ (i.e., $\rm D_{frac}^{N_2H^+} \gtrsim 0.1$) are often observed in pre-stellar cores (PSCs) and detection of $\rm N_2D^+$ is a promising method to identify elusive massive PSCs. However,…

Astrophysics of Galaxies · Physics 2021-01-13 Chia-Jung Hsu , Jonathan C. Tan , Matthew D. Goodson , Paola Caselli , Bastian Körtgen , Yu Cheng

Precipitation patterns emerging in a 2D moving front are investigated on the example of NaOH diffusing into a gel containing AlCl_3. The time evolution of the precipitate Al(OH)_3 can be observed since the precipitate redissolves in the…

Statistical Mechanics · Physics 2015-05-14 A. Volford , I. Lagzi , F. Molnar , Z. Racz

The adsorption and dissociation of H$_2$, O$_2$, and H$_2$O on Ni-Fe alloys with variable Fe:Ni ratio are studied by means of Density Functional Theory calculations. The alloy composition deeply influences the thermochemistry of the…

Materials Science · Physics 2024-10-28 Changyuan Li , Sergio Tosoni

Various mechanisms have been proposed for hydrogen embrittlement, but the causation of hydrogen-induced material degradation has remained unclear. This work shows hydrogen embrittlement due to phase instability (decomposition). In-situ…

Hydrogen and lithium, along with their compounds, are crucial materials for nuclear fusion research. High-pressure studies have revealed intricate structural transitions in all these materials. However, research on lithium hydrides beyond…

Materials Science · Physics 2024-02-27 Fude Li , Hao Wang , Jinlong Li , Hua Y. Geng

Diffusive nuclear burning of H by an underlying material capable of capturing protons can readily consume H from the surface of neutron stars (NSs) during their early cooling history. In the absence of subsequent accretion, it will be…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Philip Chang , Lars Bildsten , Phil Arras

We report a detailed high-temperature powder neutron diffraction investigation of the structural behavior of the multiferroic GaFeO3 between 296 and 1368 K. Temperature dependent neutron diffraction patterns do not show any appreciable…

Materials Science · Physics 2015-06-12 S. K. Mishra , R. Mittal , R. Singh , M. Zbiri , T. Hansen , H. Schober

Using density functional theory we examine the crystal structure and the finite-temperature thermodynamics of formation and dehydrogenation for the new quaternary hydride Li4BN3H10. Two recent studies based on X-ray and neutron diffraction…

Materials Science · Physics 2007-05-23 Donald J. Siegel , C. Wolverton , V. Ozolins

Uranium dioxide (UO$_2$), one of the most important nuclear fuels, can accumulate excess oxygen atoms as interstitial defects, which significantly impacts thermal properties. In this study, thermal conductivities and inelastic neutron…

Quantum nuclear zero-point motions in solid H$_2$ and D$_2$ under pressure are investigated at 80 K up to 160 GPa by first-principles path-integral molecular dynamics calculations. Molecular orientations are well-defined in phase II of…

Materials Science · Physics 2015-06-05 Grégory Geneste , Marc Torrent , François Bottin , Paul Loubeyre

Transition-metal centers are the active sites for many biological and inorganic chemical reactions. Notwithstanding this central importance, density-functional theory calculations based on generalized-gradient approximations often fail to…

Soft Condensed Matter · Physics 2009-11-11 Heather J. Kulik , Matteo Cococcioni , Damian A. Scherlis , Nicola Marzari

The formalism of electronic density-functional-theory, with Hubbard-U corrections (DFT+U), is employed in a computational study of the energetics of U_{1-x} Ce_x O_2 mixtures. The computational approach makes use of a procedure which…

Materials Science · Physics 2012-03-08 B. E. Hanken , C. R. Stanek , N. Grønbech-Jensen , M. Asta

Some atomic nuclei exhibit ``pear" shapes arising from octupole deformation ($\beta_3$), though direct experimental evidences for such exotic shapes remains scarce. Low-energy model studies suggest $^{238}$U may have a modest octupole…

Nuclear Theory · Physics 2025-05-15 Chunjian Zhang , Jiangyong Jia , Jinhui Chen , Chun Shen , Lumeng Liu

High levels of deuterium fraction in N$_2$H$^+$ are observed in some pre-stellar cores. Single-zone chemical models find that the timescale required to reach observed values ($D_{\rm frac}^{{\rm N}_2{\rm H}^+} \equiv {\rm N}_2{\rm D}^+/{\rm…

Solar and Stellar Astrophysics · Physics 2016-12-28 Matthew D. Goodson , Shuo Kong , Jonathan C. Tan , Fabian Heitsch , Paola Caselli

A neutron star in a long-lived, low-mass binary can easily accrete enough matter to replace its entire crust. Previous authors noted that an accreted crust, being formed from the burning of accreted hydrogen and helium, allows a series of…

Astrophysics · Physics 2009-10-31 Edward F. Brown

Phase transformations such as freezing typically start with heterogeneous nucleation. Heterogeneous nucleation near a wetting transition, of a crystalline phase is studied. The wetting transition occurs at or near a vapour-liquid transition…

Statistical Mechanics · Physics 2009-11-07 Richard P. Sear

The defect chemistry and thermal oxidation of lanthanide (Ln) incorporated-UO2 are critical for understanding and predicting their behavior as enhanced fuels, mixed oxide (MOX) fuels, spent nuclear fuels (SNF), and particles for safeguard…

This article presents a theoretical framework for enhancing nuclear fusion rates in solid-state environments under near-ambient conditions. Drawing on quantum tunneling, electron screening, and resonance energy transfer, the study proposes…

We characterize composition and structure of ultrathin nickel silicide during formation from 3 nm Ni films on Si(100) using in-situ high resolution ion scattering and high resolution transmission electron microscopy. We show the transition…

Materials Science · Physics 2020-06-24 Tuan T. Tran , Christian Lavoie , Zhen Zhang , Daniel Primetzhofer