scholarly journals Structural stability and elastic constants of precipitate phases of Mg-5%Al alloy with combined Ca and Sr addition from first-principles calculations

2016 ◽  
Author(s):  
Suqin Luo ◽  
Aitao Tang ◽  
WeiWei Du ◽  
Bin Jiang ◽  
Hanwu Dong ◽  
...  
Keyword(s):  
Structural Stability ◽  
Elastic Constants ◽  
First Principles ◽  
Al Alloy ◽  
First Principles Calculations

The structural stability, elastic constants and electronic structure of Al–Sr intermetallics by first-principles calculations

2011 ◽  
Vol 406 (19) ◽  
pp. 3681-3686 ◽  
Author(s):  
Yifang Ouyang ◽  
Fenglian Liu ◽  
Hongmei Chen ◽  
Xiaoma Tao ◽  
Yong Du ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Structural Stability ◽  
Elastic Constants ◽  
First Principles ◽  
First Principles Calculations

First-Principles Investigation of Structural Stability, Mechanical, Anisotropic, and Thermodynamic Properties of CeT2Al20 Intermetallics

2018 ◽  
Vol 73 (12) ◽  
pp. 1157-1167 ◽  
Author(s):  
He Ma ◽  
Xiaoyou Li ◽  
Wei Jiang ◽  
Xudong Zhang
Keyword(s):  
High Temperature ◽  
Thermodynamic Properties ◽  
Thermodynamic Parameters ◽  
Structural Stability ◽  
Elastic Constants ◽  
First Principles ◽  
Elastic Moduli ◽  
Formation Enthalpy ◽  
First Principles Calculations ◽  
Acoustic Velocities

AbstractFirst-principles calculations were carried out to explore the structural stability, elastic moduli, ductile or brittle behaviour, anisotropy, dynamical stability, and thermodynamic properties of pure Al and CeT2Al20 (T = Ti, V, Cr, Nb, and Ta) intermetallics. The calculated formation enthalpy and phonon frequencies confirm that these intermetallics satisfy the conditions for structural stability. The elastic constants Cij, elastic moduli B, G, and E, and the hardness Hv indicate these intermetallics have higher hardness and the better resistance against deformation than pure Al. The values of Poisson’s ratio (v) and B/G indicate that CeT2Al20 intermetallics are all brittle materials. The anisotropic constants and acoustic velocities confirm that CeT2Al20 intermetallics are all anisotropic, but CeV2Al20, CeNb2Al20, and CeTa2Al20 are nearly isotropic. Importantly, the calculated thermodynamic parameters show that CeT2Al20 intermetallics exhibit better thermodynamic properties than pure Al at high temperature.

First-Principles Investigation on Elastic Constants of TiN under High Pressure

2013 ◽  
Vol 802 ◽  
pp. 109-113
Author(s):  
Kittiya Prasert ◽  
Pitiporn Thanomngam ◽  
Kanoknan Sarasamak
Keyword(s):  
Elastic Constants ◽  
First Principles ◽  
Local Density ◽  
Ambient Pressure ◽  
Lattice Parameter ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Shear Distortion ◽  
Calculated Lattice Parameter

Elastic constants of NaCl-type TiN under pressure were investigated by first-principles calculations within both local density approximation (LDA) and Perdew-Burke-Ernzerhof generalized-gradient approximation (PBE-GGA). At ambient pressure, the calculated lattice parameter, bulk modulus, and elastic constants of NaCl-type TiN are in well agreement with other available values. Under pressure, all elastic constants,C11,C12, andC44, are found to increase with pressure.C11, which is related to the longitudinal distortion, increases rapidly with pressure whileC12andC44which are related to the transverse and shear distortion, respectively, are much less sensitive to pressure.

scholarly journals Temperature Effects on the Elastic Constants, Stacking Fault Energy and Twinnability of Ni3Si and Ni3Ge: A First-Principles Study

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 364 ◽  
Author(s):  
Lili Liu ◽  
Liwan Chen ◽  
Youchang Jiang ◽  
Chenglin He ◽  
Gang Xu ◽  
...  
Keyword(s):  
Elastic Constants ◽  
First Principles ◽  
Antiphase Boundary ◽  
Stacking Fault ◽  
First Principles Calculations ◽  
Planar Fault ◽  
Different Temperatures ◽  
Generalized Stacking Fault ◽  
Increasing Temperature ◽  
Stacking Fault Energies

The volume versus temperature relations for Ni 3 Si and Ni 3 Ge are obtained by using the first principles calculations combined with the quasiharmonic approach. Based on the equilibrium volumes at temperature T, the temperature dependence of the elastic constants, generalized stacking fault energies and generalized planar fault energies of Ni 3 Si and Ni 3 Ge are investigated by first principles calculations. The elastic constants, antiphase boundary energies, complex stacking fault energies, superlattice intrinsic stacking fault energies and twinning energy decrease with increasing temperature. The twinnability of Ni 3 Si and Ni 3 Ge are examined using the twinnability criteria. It is found that their twinnability decrease with increasing temperature. Furthermore, Ni 3 Si has better twinnability than Ni 3 Ge at different temperatures.

scholarly journals Physical Properties Investigations of Ternary-Layered Carbides M2PbC (M = Ti, Zr and Hf): First-Principles Calculations

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1445
Author(s):  
Tahani A. Alrebdi ◽  
Mohammed Benali Kanoun ◽  
Souraya Goumri-Said
Keyword(s):  
Elastic Constants ◽  
First Principles ◽  
Mechanical Stability ◽  
Electronic Band Structure ◽  
Max Phase ◽  
Mechanical And Thermal Properties ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Bonding Properties ◽  
Structure Density

We investigated structure optimization, mechanical stability, electronic and bonding properties of the nanolaminate compounds Ti2PbC, Zr2PbC, and Hf2PbC using the first-principles calculations. These structures display nanolaminated edifices where MC layers are interleaved with Pb. The calculation of formation energies, elastic moduli and phonons reveal that all MAX phase systems are exothermic, and are intrinsically and dynamically stable at zero and under pressure. The mechanical and thermal properties are reported with fundamental insights. Results of bulk modulus and shear modulus show that the investigated compounds display a remarkable hardness. The elastic constants C11 and C33 rise more quickly with an increase in pressure than that of other elastic constants. Electronic and bonding properties are investigated through the calculation of electronic band structure, density of states, and charge densities.

scholarly journals Phase Stability and Magnetic Properties of Mn3Z (Z = Al, Ga, In, Tl, Ge, Sn, Pb) Heusler Alloys

2019 ◽  
Vol 9 (5) ◽  
pp. 964 ◽  
Author(s):  
Haopeng Zhang ◽  
Wenbin Liu ◽  
Tingting Lin ◽  
Wenhong Wang ◽  
Guodong Liu
Keyword(s):  
Magnetic Properties ◽  
Structural Stability ◽  
Phase Stability ◽  
First Principles ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Atomic Radius ◽  
Tetragonal Distortion ◽  
Stable Phase ◽  
First Principles Calculations

The structural stability and magnetic properties of the cubic and tetragonal phases of Mn3Z (Z = Ga, In, Tl, Ge, Sn, Pb) Heusler alloys are studied by using first-principles calculations. It is found that with the increasing of the atomic radius of Z atom, the more stable phase varies from the cubic to the tetragonal structure. With increasing tetragonal distortion, the magnetic moments of Mn (A/C and B) atoms change in a regular way, which can be traced back to the change of the relative distance and the covalent hybridization between the atoms.

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