Elastic Properties and Electronic Structures of L12-TiAl3 and L12-Ti(Al,Pt)3: A Density Functional Theory Investigation

2015 ◽  
Vol 817 ◽  
pp. 816-825
Author(s):  
Bo Huang ◽  
Yong Hua Duan ◽  
Sun Yong ◽  
Ming Jun Peng
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Elastic Parameters ◽  
Electronic Density ◽  
Functional Theory ◽  
Experimental Values

First-principles calculations have been carried out to investigate the elastic properties and electronic structures of L12-TiAl3and L12-Ti (Al, Pt)3. The optimized structural parameters were largely consistent with the experimental values. The electronic density of states (DOS) and the differences of charge density distribution were given. The independent single-crystal elastic constants and polycrystalline elastic parameters such as bulk modulusB, Young’s modulusE, shear modulusG, Poisson’s ratioνand anisotropy valueAhave been calculated by Voigt-Reuss-Hill averaging scheme. The results indicate that the L12-Ti (Al, Pt)3exhibits larger anisotropy and more ductile than L12-TiAl3.

First-principles calculations of stability, electronic and elastic properties of the precipitates present in 7055 aluminum alloy

2018 ◽  
Vol 32 (09) ◽  
pp. 1850104 ◽  
Author(s):  
Cheng Huang ◽  
Hongbang Shao ◽  
Yunlong Ma ◽  
Yuanchun Huang ◽  
Zhengbing Xiao
Keyword(s):  
Aluminum Alloy ◽  
Elastic Properties ◽  
Structural Stability ◽  
First Principles ◽  
Density Functional ◽  
Elastic Anisotropy ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Functional Theory ◽  
7055 Aluminum Alloy

The structural stability, electronic structures and elastic properties of the strengthening precipitates, namely Al3Zr, MgZn2, Al2CuMg and Al2Cu, present in 7055 aluminum alloy were investigated by the first-principles calculations based on density functional theory (DFT). The optimized structural parameters are in good agreement with literature values available. It is found that Al3Zr has the strongest alloying ability and structural stability, while for MgZn2, its structural stability is the worst. The calculated electronic results indicate that covalent bonding is the dominant cohesion of Al3Zr, whereas the fractional ionic interactions coexisting with metallic bonding are found in MgZn2, Al2CuMg and Al2Cu. The elastic constants C[Formula: see text] of these precipitates were calculated, and the bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and universal elastic anisotropy were derived. It is suggested that MgZn2 is ductile, whereas Al3Zr, Al2CuMg and Al2Cu are brittle, and the elastic anisotropies of them increase in the following sequence: Al3Zr[Formula: see text]MgZn2[Formula: see text]Al2CuMg[Formula: see text]Al2Cu. The formation of MgZn2 and Al3Zr should be promoted by increasing the compositions of Zn and Zr to improve the alloy’s performance further.

Structural and Elastic Properties of Antimony Triiodide from First-Principles Calculations

2013 ◽  
Vol 750-752 ◽  
pp. 1782-1785
Author(s):  
Xiao Xiao Sun ◽  
Chun Lei Wu ◽  
Wei Wei Chen ◽  
Hai Sheng Liu
Keyword(s):  
Experimental Data ◽  
Elastic Properties ◽  
First Principles ◽  
Density Functional ◽  
Elastic Anisotropy ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Space Groups ◽  
Calculated Equilibrium

First principles calculations are performed to investigate the structural and elastic properties of SbI3 based on density functional theory for two space groups: trigonal R-3 and monoclinic P21/c. The calculated equilibrium structural parameters agree well with the experimental data. The enthalpy calculations confirm that the trigonal R-3 structure of SbI3 is the most stable structure at zero pressure. For R-3 structure, the obtained bulk, shear, and Youngs modulus are 28.1, 15.2 and 38.6 GPa, respectively. The calculated Debye temperature is 197 K. SbI3 presents large elastic anisotropy, stronger compressibility and better ductility at 0 GPa.

Probing the electronic structures of Con (n = 1–5) clusters on γ-Al2O3 surfaces using first-principles calculations

2017 ◽  
Vol 19 (5) ◽  
pp. 3679-3687 ◽  
Author(s):  
Tao Yang ◽  
Masahiro Ehara
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
First Principles Calculations ◽  
Functional Theory

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.

THEORETICAL INVESTIGATION OF THE ELASTIC PROPERTIES AND LATTICE DYNAMICS OF THE MgSxSe1-x ALLOY

2007 ◽  
Vol 21 (05) ◽  
pp. 249-259 ◽  
Author(s):  
K. BOUAMAMA ◽  
P. DJEMIA
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Local Density ◽  
Lattice Parameter ◽  
First Principles Calculations ◽  
Virtual Crystal Approximation ◽  
Functional Theory ◽  
Density Functional Perturbation Theory

Structural and elastic properties as well as lattice dynamics of ternary MgS x Se 1-x alloy have been studied using first-principles calculations. These are done using density functional theory (DFT) and density functional perturbation theory (DFPT) within the local density approximation (LDA) and employing the virtual-crystal approximation (VCA). We found that the lattice parameter, the elastic constants and the phonon frequencies follow a quadratic law in x.

Calculation of electronic structure and mechanical properties of DO3–Fe75-xSi25Nix intermetallic compounds by first principles

2015 ◽  
Vol 29 (13) ◽  
pp. 1550087
Author(s):  
R. Ma ◽  
M. P. Wan ◽  
J. Huang ◽  
Q. Xie
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Elastic Parameters ◽  
Functional Theory ◽  
Ni Content ◽  
The Density Functional Theory ◽  
The Difference

Based on the density functional theory (DFT), the plane-wave pseudopotential method was used to investigate the electronic structures and mechanical properties of DO 3– Fe 75-x Si 25 Ni x(x = 0, 3.125, 6.25 and 9.375) intermetallic compounds. The elastic parameters were calculated, and then the bulk modulus, shear modulus and elastic modulus were derived. The paper then focuses on the discussion of ductility and plasticity. The results show that by adding appropriate Ni to Fe 3 Si intermetallic compound can improve the ductility. But the hardness will increase when the Ni content exceeds 6.25%. Analysis of density of states (DOS) and overlap populations indicates that with the difference of the strength of bonding and activity, there were some differences of ductility among different Ni contents. The Fe 71.875 Ni 3.125 Si 25 has the lowest hardness because the covalent bonding (Fe–Si bond and Si–Ni bond) has the minimum covalent electrons.

scholarly journals ELASTIC PROPERTIES OF TRANSITION METAL DIOXIDES: XO2 (X = Ru, Rh, Os, andIr)

2008 ◽  
Vol 19 (08) ◽  
pp. 1269-1275 ◽  
Author(s):  
YANLING LI ◽  
ZHI ZENG
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Shear Modulus ◽  
Elastic Properties ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Debye Temperatures ◽  
Metal Dioxides

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.

First-principles study of the structural and elastic properties of Ti5Si3 with substitutions Zr, V, Nb, and Cr

2010 ◽  
Vol 25 (12) ◽  
pp. 2317-2324 ◽  
Author(s):  
Hui-Yuan Wang ◽  
Wen-Ping Si ◽  
Shi-Long Li ◽  
Nan Zhang ◽  
Qi-Chuan Jiang
Keyword(s):  
Density Functional Theory ◽  
Elastic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Elastic Moduli ◽  
Site Occupancy ◽  
Formation Enthalpy ◽  
Functional Theory ◽  
The Density Functional Theory

The formation enthalpy, electronic structures, and elastic moduli of the intermetallic compound Ti5Si3 with substitutions Zr, V, Nb, and Cr are investigated by using first-principles methods based on the density-functional theory. Our calculation shows that the site occupancy behaviors of alloying elements in Ti5Si3, determined by their atom radius, are consistent with the available experimental observations. Furthermore, using the Voigt–Reuss–Hill (VRH) approximation method, we obtained the bulk modulus B, shear modulus G, and the Young’s modulus E. Among these four substitutions, the V, Nb, and Cr substitutions can improve the ductility of Ti5Si3 effectively, while Zr substitution has little effect on the elastic properties of Ti5Si3. The elastic property variations of Ti5Si3 due to different substitutions are found to be correlated with the Me4d–Me4d antibonding and the strengthened Me4d–Si bonding in the solids.

scholarly journals Elastic Properties and Electronic Properties of MxNy (M = Ti, Zr) from First Principles Calculations

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1640 ◽  
Author(s):  
Yangqi Ji ◽  
Xiaoli Yuan
Keyword(s):  
Electronic Properties ◽  
Elastic Properties ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Central Force ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Space Group ◽  
Group I

The elastic properties and electronic properties of MxNy (M = Ti, Zr) TiN, Ti2N, Zr3N4, ZrN with different structures have been investigated using density functional theory. Through the calculation of the elastic constants, it was found that all of these structures meet the mechanical stability except for ZrN with space group P63mc. Their mechanical properties are studied by a comparison of various parameters. The stiffness of TiN is larger than that of ZrN with space group Fm 3 ¯ m. Ti2N’s stiffness with space group I41/amdz is larger than Ti2N with space group P42/mnm. Zr3N4’s stiffness with space group Pnam is largest in three structures of Zr3N4. TiN, Ti2N and ZrN are non-central force, Zr3N4 is central force. TiN and ZrN with space group Fm 3 ¯ m are brittle, and TiN is brittler than ZrN with space group Fm 3 ¯ m. The two kinds of Ti2N are brittle and Ti2N with space group I41/amdz is larger. Three structures of Zr3N4 are tough and Zr3N4 with space group I 4 ¯ 3d is the toughest. Meanwhile, the electronic properties of TiN, Ti2N, Zr3N4 and ZrN were calculated, possible superconducting properties of the studied materials were predicted.

Structural Phase Transition and Electronic Properties of MgCe under High Pressure from First-Principles Calculations

2014 ◽  
Vol 577 ◽  
pp. 102-107
Author(s):  
Qiu Xiang Liu ◽  
De Ping Lu ◽  
Rui Jun Zhang ◽  
Lei Lu ◽  
Shi Fang Xie
Keyword(s):  
Phase Transition ◽  
Ground State ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
High Pressures ◽  
Local Density ◽  
Structural Phase ◽  
First Principles Calculations ◽  
Functional Theory

The structural stability of MgCe under high pressures has been investigated by using the first-principles plane-wave pseudopotential density functional theory within the local density approximation (LDA). The obtained results predict that MgCe in the Ba structure is predicted to be the most stable structure corresponding to the ground state, because of lowest total energy. MgCe undergoes a pressure-induced phase transition from the Ba structure to B32 structure at 36 GPa. And no further transition is found up to 120 GPa. In addition, the electronic structures of four structures of MgCe are also calculated and discussed.

Electronic, Optical and Vibrational Properties of B3N3H6 from First-Principles Calculations

2021 ◽  
Author(s):  
Yun-Dan Gan ◽  
Han Qin ◽  
Fu-Sheng Liu ◽  
Zheng-Tang Liu ◽  
Cheng lu Jiang ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Conductivity Loss ◽  
Good Agreement

Abstract The electronic, optical and vibrational properties of B3N3H6 have been calculated by means of first-principles density functional theory (DFT) calculations within the generalized gradient approximation (GGA) and the local density approximation (LDA). The calculated structural parameters of B3N3H6 are in good agreement with experimental work. With the band structure and density of states (DOS), we have analyzed the optical properties including the complex dielectric function, refractive index, absorption, conductivity, loss function and reflectivity. By the contrast, it is found that on the (001) component and (100) component have obvious optical anisotropy. Moreover, the vibrational properties have been obtained and analyzed.

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