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.

Back calculation of parent austenite orientation using a clustering approach

2013 ◽  
Vol 46 (1) ◽  
pp. 210-215 ◽  
Author(s):  
V. Tari ◽  
A. D. Rollett ◽  
H. Beladi
Keyword(s):  
Face Centered Cubic ◽  
Orientation Relationships ◽  
New Approach ◽  
Austenite Grain ◽  
Parent Orientation ◽  
Back Calculation ◽  
Clustering Approach ◽  
Face Centered ◽  
Parent Austenite ◽  
Good Agreement

A new approach is presented for calculating the parent orientation from sets of variants of orientations produced by phase transformation. The parent austenite orientation is determined using the orientations of bainite variants that transformed from a single parent austenite grain. In this approach, the five known orientation relationships are used to back transform each observed bainite variant to all their potential face-centered-cubic (f.c.c.) parent orientations. A set of potential f.c.c. orientations has one representative from each bainite variant, and each set is assembled on the basis of minimum mutual misorientation. The set of back-transformed orientations with the minimum summation of mutual misorientation angle (SMMA) is selected as the most probable parent (austenite) orientation. The availability of multiple sets permits a confidence index to be calculated from the best and next best fits to a parent orientation. The results show good agreement between the measured parent austenite orientation and the calculated parent orientation having minimum SMMA.

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 Synthesis of Non-Stoichiometric (TiNb)C0.5 with High Hardness and Fracture Toughness under HTHP

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1219
Author(s):  
Zhichao Zhang ◽  
Hu Tang ◽  
Yujiao Ke ◽  
Yu Li ◽  
Xiaochen Jiao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Pressures ◽  
Raw Materials ◽  
High Hardness ◽  
High Strength ◽  
Phase Identification ◽  
Face Centered Cubic ◽  
Covalent Bonds ◽  
Synthetic Strategy ◽  
Face Centered

Nonstoichiometric TiC0.5 and (TiNb)0.5 powders were prepared by the mechanical alloying process using Ti, Nb, and TiC powders as raw materials. Furthermore, the as-prepared TiC0.5 and (TiNb)0.5 powders were used as initial materials to fabricate TiC0.5 and (TiNb)0.5 compacts under high pressures and high temperatures (HTHP) of 5.5 GPa and 1200–1550 °C for 5 min. Phase identification and microstructure of the mechanical-alloyed powders and the sintered TiC0.5 and (TiNb)0.5 compacts were realized by an X-ray diffractometer and scanning electron microscope. The results indicate that the as-prepared TiC0.5 and (TiNb)0.5 powders have a similar crystal structure of face-centered cubic (FCC) to TiC. The sintered (TiNb)0.5 compact has good Vickers hardness (~16 GPa), and notably, excellent fracture toughness (~7.3 MPa·m1/2). The non-stoichiometric compound not only reduced the sintering temperature of covalent compounds, but also greatly enhanced the mechanical properties of the materials. Thus, we have provided a novel synthetic strategy for the production of a compound with high-strength covalent bonds.

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.

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