scholarly journals Melting curve of face-centered-cubic nickel from first-principles calculations

2013 ◽  
Vol 88 (2) ◽  
Author(s):  
Monica Pozzo ◽  
Dario Alfè
Keyword(s):  
First Principles ◽  
Melting Curve ◽  
Face Centered Cubic ◽  
First Principles Calculations ◽  
Face Centered

First-principles study of hydrogen trapping behavior in face centered cubic metals (M=Ni, Cu and Al) with monovacancy

2020 ◽  
Vol 45 (46) ◽  
pp. 25555-25566
Author(s):  
Weiwei Xing ◽  
Xing-Qiu Chen ◽  
Xiaobing Li ◽  
Yingche Ma ◽  
Bo Chen ◽  
...  
Keyword(s):  
First Principles ◽  
Face Centered Cubic ◽  
Hydrogen Trapping ◽  
Cubic Metals ◽  
First Principles Study ◽  
Face Centered

scholarly journals In situ characterization of the high pressure – high temperature melting curve of platinum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Simone Anzellini ◽  
Virginia Monteseguro ◽  
Enrico Bandiello ◽  
Agnès Dewaele ◽  
Leonid Burakovsky ◽  
...  
Keyword(s):  
Melting Curve ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Melting Line ◽  
Diamond Anvil Cells ◽  
High Pressure High Temperature ◽  
The Face ◽  
Diamond Anvil ◽  
Face Centered ◽  
Laser Heated

Abstract In this work, the melting line of platinum has been characterized both experimentally, using synchrotron X-ray diffraction in laser-heated diamond-anvil cells, and theoretically, using ab initio simulations. In the investigated pressure and temperature range (pressure between 10 GPa and 110 GPa and temperature between 300 K and 4800 K), only the face-centered cubic phase of platinum has been observed. The melting points obtained with the two techniques are in good agreement. Furthermore, the obtained results agree and considerably extend the melting line previously obtained in large-volume devices and in one laser-heated diamond-anvil cells experiment, in which the speckle method was used as melting detection technique. The divergence between previous laser-heating experiments is resolved in favor of those experiments reporting the higher melting slope.

A New Approach for Calculating Cohesive Energy of Solid Neon Based on the First Principles

2019 ◽  
Vol 807 ◽  
pp. 128-134
Author(s):  
Xing Rong Zheng
Keyword(s):  
First Principles ◽  
Cohesive Energy ◽  
High Pressures ◽  
New Combination ◽  
Rare Gas ◽  
Face Centered Cubic ◽  
New Approach ◽  
Molecular Systems ◽  
Ionic Systems ◽  
Face Centered

Based on the first principles and quantum mechanics, a new approach is put forward to calculate the cohesive energy of face-centered cubic solid neon, in which both the two-body and the total many-body interaction potentials are reasonably emphasized by a new combination formula. It shows that the new scheme is a simple and accurate tool to understand the high-pressure behaviors of solid neon, and it will be applied to calculate the compression curves of dense Helium, Argon, Krypton and Xenon at very high pressures. It is expected that this method can be applicable to all rare gas, including the gas, solid, and liquid phase regions, even of molecular systems, ionic systems.

scholarly journals Hydrogen Solubility in Pd3Ag Phases from First-Principles Calculation

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 121 ◽  
Author(s):  
Liang Chen ◽  
Qian Wang ◽  
Wugui Jiang ◽  
Haoran Gong
Keyword(s):  
First Principles ◽  
Defect Formation ◽  
First Principles Calculation ◽  
Hydrogen Solubility ◽  
Present Calculation ◽  
Face Centered Cubic ◽  
Fundamental Properties ◽  
Formation Enthalpies ◽  
Potential Applications ◽  
Face Centered

First-principles calculation was used to systematically investigate hydrogen solubility in Pd3Ag phases. It was found that the solubility of hydrogen in Pd3Ag phases was much greater than in face-centered cubic (FCC) Pd, suggesting that Ag atoms enhanced hydrogen solubility with respect to FCC Pd. In addition, the present calculation also revealed that the anti-site defect formation enthalpies of Pd3Ag were close to zero, and the values of vacancy were positive and large, which indicated that Pd3Ag distributed compactly. In the process of hydrogen separation, anti-site defects decreased the hydrogen solubility in the Pd3Ag phases, i.e., the ordered Pd3Ag phases bestowed excellent properties of H selectivity. The results presented not only explore the fundamental properties of Pd3Ag phases and their various potential applications, but also agree with experimental observations reported in the literature.

Pressure-induced vibrational and superconducting properties of lanthanum hydrides from first principles calculations

2015 ◽  
Vol 93 (12) ◽  
pp. 1630-1637 ◽  
Author(s):  
De-Chun He ◽  
Han-Xiao Shao ◽  
Yong-Kai Wei
Keyword(s):  
First Principles ◽  
Phonon Dispersion ◽  
Theoretical Calculations ◽  
Underlying Mechanism ◽  
Face Centered Cubic ◽  
Superconducting Transition ◽  
First Principles Calculations ◽  
Superconducting Properties ◽  
Hydrogen Atoms ◽  
Octahedral Sites

Pressure-induced vibrational and superconducting properties of lanthanum hydrides (LaH2 and LaH3) have been studied using first principles calculations. It is found that LaH2 and LaH3 are dynamically stable in the pressure ranges of 0–39 GPa and 4–35 GPa, respectively. The character of phonon dispersion curves for LaH2 and LaH3 is analyzed under pressure. The zone-center phonon mode eigen displacements that represent infrared and Raman activity are also obtained, which are essential to the analysis of spectral experiments. The calculations based on Bardeen–Cooper–Schrieffer theory indicate that LaH2 almost has no superconducting behavior even under pressure, in reasonable agreement with previous theoretical calculations and experiments. Whereas, LaH3 presents a considerable high superconducting transition temperature (Tc) at the onset of the face centered cubic structure, while it decreases exponentially under further compression up to 25 GPa and finally almost approaches zero. Further analysis indicates that the underlying mechanism of these two distinct superconducting behaviors are closely related to the hybridization between the HO-s state and La-d state. The mode Grüneisen parameters of two hydrides are also analyzed under 35 GPa, finding that the hydrogen atoms at octahedral sites are responsible for the superconducting properties of LaH3, and in fact, the unobserved superconducting behavior in LaH2 can be interpreted as the absence of hydrogen at octahedral sites compared with LaH3.

First-principles LDA+U calculations investigating the lattice contraction of face-centered cubic Pu hydrides

2012 ◽  
Vol 424 (1-3) ◽  
pp. 183-189 ◽  
Author(s):  
B.Y. Ao ◽  
X.L. Wang ◽  
P. Shi ◽  
P.H. Chen ◽  
X.Q. Ye ◽  
...  
Keyword(s):  
First Principles ◽  
Face Centered Cubic ◽  
Lattice Contraction ◽  
Face Centered

Theoretical Investigation of Carbon Atom Adsorption and Diffusion on the Surfaces of Cu

2014 ◽  
Vol 1082 ◽  
pp. 475-479
Author(s):  
Liang Qiao ◽  
Shu Jie Liu ◽  
Xiao Ying Hu ◽  
Li Li Wang ◽  
Dong Mei Bi
Keyword(s):  
Carbon Atom ◽  
First Principles ◽  
Density Functional ◽  
Energy Difference ◽  
Face Centered Cubic ◽  
Functional Theory ◽  
Hexagonal Close Packed ◽  
Adsorbed Carbon ◽  
Face Centered ◽  
And Diffusion

The adsorption and diffusion of carbon atom on Cu (111) and (100) surfaces have been investigated based on first-principles density-functional theory. For Cu (111) surface, the hexagonal close-packed and face-centered cubic sites are the most stable sites with little energy difference in the adsorption energy. For Cu (100) surface, the hollow site is the most stable. There is charge transfer from Cu surface to the adsorbed carbon atom. Moreover, the diffusions of carbon atom on Cu surfaces have been investigated, and the results show that the diffusion of carbon atom prefers to happen on Cu (111) surface.

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