scholarly journals First-Principles Study of the Structural Stability and Electronic and Elastic Properties of Helium inα-Zirconium

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jian Zheng ◽  
Huijun Zhang ◽  
Xiaosong Zhou ◽  
Jianhua Liang ◽  
Liusi Sheng ◽  
...  

First-principles calculations within density functional theory have been performed to investigate the behaviors of helium inα-zirconium. The most favorable interstitial site for He inα-Zr is not an ordinary tetrahedral or octahedral site, but a basal octahedral site with a formation energy as low as 2.40 eV. The formation energy reduces to 1.25 eV in the presence of preexisting vacancies. The analysis on the density of states and the charge density has been carried out. In addition, the influences of He and small He-V complexes on the elastic properties have been studied. The He-V complexes have been found to greatly affect the elastic properties compared with He alone.

2008 ◽  
Vol 19 (08) ◽  
pp. 1269-1275 ◽  
Author(s):  
YANLING LI ◽  
ZHI ZENG

The elastic properties of rutile transition metal dioxides XO2 ( X = Ru , Rh , Os , and Ir ) are investigated using first-principles calculations based on density functional theory. Elastic constants, bulk modulus, shear modulus, and Young's modulus as well as Possion ratio are given. OsO 2 and IrO 2 show strong incompressibility. The hardness estimated for these dioxides shows that they are not superhard solids. The obtained Debye temperatures are comparative to those of transition metal dinitrides or diborides.


2018 ◽  
Vol 32 (10) ◽  
pp. 1850065 ◽  
Author(s):  
Jinming Li ◽  
Xiaobo Li ◽  
Haiyun Gao ◽  
Dian Peng

The content of this study is to analyze the electronic structure and elastic properties that the different structures of Mo2NiB2 and doping with V of the tetragonal M3B2 (Mo2Ni[Formula: see text]V[Formula: see text]B2 and Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2) (x = 0.25, 0.5, 0.75 and y = 0.125, 0.25, 0.375) by first-principles calculations based on density functional theory (DFT) combined with the projection-plus-wave method. But the calculated formation energy shows that V atoms prefer to substitute the Mo and Ni atoms of the tetragonal Mo2NiB2. Moreover, with the increase of V content, the formation enthalpy of tetragonal Mo2NiB2 is reduced, and the formation enthalpy of Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2 is the least as −53.23 kJ/mol. The calculated elastic constant suffices the condition of mechanical stability, indicate that they are stable. The calculated elastic modulus illustrates that Mo2NiB2 having better mechanical properties when V elements are at Mo and Ni sites instead of Ni sites. The calculated and analyzed density of states of Mo[Formula: see text]Ni[Formula: see text]V[Formula: see text]B2 has the smallest the density of states at the Fermi level indicating that it has the more stable structure. For the theoretical analysis of the first-principles calculations, the addition of 15 atom% of the V and V doping modes of Mo and Ni are preferentially replaced by V atoms of Mo2NiB2 ternary boride has the best performance.


2021 ◽  
Author(s):  
H. R. Mahida ◽  
Deobrat Singh ◽  
Yogesh Sonvane ◽  
Sanjeev K. Gupta ◽  
P. B. Thakor ◽  
...  

In the present study, we have investigated the structural, electronic, and charge transport properties of pristine, hydrogenated, and oxidized Si2BN monolayers via first-principles calculations based on density functional theory (DFT).


2017 ◽  
Vol 19 (5) ◽  
pp. 3679-3687 ◽  
Author(s):  
Tao Yang ◽  
Masahiro Ehara

Using density functional theory calculations, we discussed the geometric and electronic structures and nucleation of small Co clusters on γ-Al2O3(100) and γ-Al2O3(110) surfaces.


2015 ◽  
Vol 17 (45) ◽  
pp. 30598-30605 ◽  
Author(s):  
Ming-Kai Hsiao ◽  
Chia-Hao Su ◽  
Ching-Yang Liu ◽  
Hui-Lung Chen

We employed monolayer tungsten metal to modify the Fe(111) surface, denoted as W@Fe(111), and calculated the adsorption and dehydrogenation behaviors of NH3 on W@Fe(111) surface via first-principles calculations based on density functional theory (DFT).


2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.


2009 ◽  
Vol 1200 ◽  
Author(s):  
Markus E. Gruner

AbstractThis contribution reports static ionic displacements in ferromagnetic disordered Fe70Pd30 alloys obtained by relaxation of the ionic positions of a 108-atom supercell within the framework of density functional theory. Comparison with a simple statistical model based on Lennard-Jones pair interactions reveals that these displacements are significantly larger than can be explained by the different sizes of the elemental constituents. The discrepancies are presumably related to collective displacements of the Fe atoms. Corresponding distortions are experimentally observed for ordered Fe3Pt and predicted by first-principles calculations for all ordered Fe-rich L12 alloys with Ni group elements and originate from details of the electronic structure at the Fermi level.


RSC Advances ◽  
2019 ◽  
Vol 9 (44) ◽  
pp. 25900-25911 ◽  
Author(s):  
Esmaeil Pakizeh ◽  
Jaafar Jalilian ◽  
Mahnaz Mohammadi

In this study, based on the density functional theory and semi-classical Boltzmann transport theory, we investigated the structural, thermoelectric, optical and phononic properties of the Fe2ZrP compound.


2020 ◽  
Vol 22 (17) ◽  
pp. 9677-9684 ◽  
Author(s):  
Mehdi Ghambarian ◽  
Zahra Azizi ◽  
Mohammad Ghashghaee

A drastic improvement in the phosgene sensitivity of black phosphorene with defect engineering is reported for the first time within a periodic density functional theory framework.


2017 ◽  
Vol 19 (23) ◽  
pp. 15021-15029 ◽  
Author(s):  
Yusheng Wang ◽  
Nahong Song ◽  
Min Jia ◽  
Dapeng Yang ◽  
Chikowore Panashe ◽  
...  

First principles calculations based on density functional theory were carried out to study the electronic and magnetic properties of C2N nanoribbons (C2NNRs).


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