Phase stability, elastic anisotropy and electronic structure of cubic MAl2(M = Mg, Ca, Sr and Ba) Laves phases from first-principles calculations

2016 ◽  
Vol 3 (10) ◽  
pp. 106505 ◽  
Author(s):  
Yuanyuan Kong ◽  
Yonghua Duan ◽  
Lishi Ma ◽  
Runyue Li
Keyword(s):  
Electronic Structure ◽  
Phase Stability ◽  
First Principles ◽  
Elastic Anisotropy ◽  
First Principles Calculations ◽  
Laves Phases

The stability, electronic structure, elastic and metallic properties of manganese nitrides

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1620-1627 ◽  
Author(s):  
Ran Yu ◽  
Xiaoyu Chong ◽  
Yehua Jiang ◽  
Rong Zhou ◽  
Wen Yuan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Phase Stability ◽  
First Principles ◽  
First Principles Calculations ◽  
The Stability

The phase stability, electronic structure, and elastic and metallic properties of manganese nitrides (Mn4N, Mn2N0.86, Mn3N2, and MnN) were extensively studied by first principles calculations.

Structural and elastic properties of Cu6Sn5 and Cu3Snfrom first-principles calculations

2009 ◽  
Vol 24 (7) ◽  
pp. 2361-2372 ◽  
Author(s):  
Jiunn Chen ◽  
Yi-Shao Lai ◽  
Ping-Feng Yang ◽  
Chung-Yuan Ren ◽  
Di-Jing Huang
Keyword(s):  
Electronic Structure ◽  
Elastic Modulus ◽  
Elastic Properties ◽  
First Principles ◽  
Elastic Anisotropy ◽  
Lattice Structure ◽  
Elastic Stiffness ◽  
First Principles Calculations ◽  
Atomic Lattice ◽  
Microstructure Effect

We investigated the elastic properties of two tin-copper crystalline phases, the η′-Cu6Sn5 and ε-Cu3Sn, which are often encountered in microelectronic packaging applications. The full elastic stiffness of both phases is determined based on strain-energy relations using first-principles calculations. The computed results show the elastic anisotropy of both phases that cannot be resolved from experiments. Our results, suggesting both phases have the greatest stiffness along the c direction, particularly showed the unique in-plane elastic anisotropy associated with the lattice modulation of the Cu3Sn superstructure. The polycrystalline moduli obtained using the Voigt-Reuss scheme are 125.98 GPa for Cu6Sn5 and 134.16 GPa for Cu3Sn. Our data analysis indicates that the smaller elastic moduli of Cu6Sn5 are attributed to the direct Sn–Sn bond in Cu6Sn5. We reassert the elastic modulus and hardness of both phases using the nanoindentation experiment for our calculation benchmark. Interestingly, the computed polycrystalline elastic modulus of Cu6Sn5 seems to be overestimated, whereas that of Cu3Sn falls nicely in the range of reported data. Based on the observations, the elastic modulus of Cu6Sn5 obtained from nanoindentation tests admit the microstructure effect that is absent for Cu3Sn is concluded. Our analysis of electronic structure shows that the intrinsic hardness and elastic modulus of both phases are dominated by electronic structure and atomic lattice structure, respectively.

First-principles investigation of possible martensitic transformation and magnetic properties of Heusler-type Pt2-xMn1+xIn alloys

2015 ◽  
Vol 08 (06) ◽  
pp. 1550064 ◽  
Author(s):  
Lin Feng ◽  
Wenxing Zhang ◽  
Enke Liu ◽  
Wenhong Wang ◽  
Guangheng Wu
Keyword(s):  
Magnetic Properties ◽  
Phase Transformation ◽  
Electronic Structure ◽  
Martensitic Transformation ◽  
Phase Stability ◽  
First Principles ◽  
Electronic Structures ◽  
First Principles Calculations ◽  
Magnetic Structures

The phase stability, electronic structure and magnetism of Pt 2-x Mn 1+x In (x = 0, 0.25, 0.5, 0.75, 1) alloys are studied by first-principles calculations. The possible magnetic martensitic transformation in this series has been investigated. For all the five compounds, the energy minimums occur around c/a = 1.30, and the energy differences between the austenitic and martensitic phases are large enough to overcome the resistance of phase transformation. By comparing the electronic structures of austenitic and martensitic phases, we can find that the phase stability is enhanced by the martensitic transformation. The magnetic structures of the austenitic and martensitic phases are also discussed.

scholarly journals Phase Stability, Elastic Modulus and Elastic Anisotropy of X Doped (X = Zn, Zr and Ag) Al3Li: Insight from First-Principles Calculations

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
Jinzhong Tian ◽  
Yuhong Zhao ◽  
Shengjie Ma ◽  
Hua Hou
Keyword(s):  
Phase Stability ◽  
First Principles ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
First Principles Calculations ◽  
Stability Criteria ◽  
Longitudinal Sound Velocity ◽  
Positive Effect ◽  
Shear Planes

In present work, the effects of alloying elements X (X = Zn, Zr and Ag) doping on the phase stability, elastic properties, anisotropy and Debye temperature of Al3Li were studied by the first-principles method. Results showed that pure and doped Al3Li can exist and be stable at 0 K. Zn and Ag elements preferentially occupy the Al sites and Zr elements tend to occupy the Li sites. All the Cij obey the mechanical stability criteria, indicating the mechanical stability of these compounds. The overall anisotropy decreases in the following order: Al23Li8Ag > Al3Li > Al23Li8Zn > Al24Li7Zr, which shows that the addition of Zn and Zr has a positive effect on reducing the anisotropy of Al3Li. The shear anisotropic factors for Zn and Zr doped Al3Li are very close to one, meaning that elastic moduli do not strongly depend on different shear planes. For pure and doped Al3Li phase, the transverse sound velocities νt1 and νt2 among the three directions are smaller than the longitudinal sound velocity νl. Moreover, only the addition of Zn is beneficial to increasing the ΘD of Al3Li among the three elements.

Phase stability, electronic structure and equation of state of cubic TcN from first-principles calculations

2016 ◽  
Vol 380 (38) ◽  
pp. 3144-3148 ◽  
Author(s):  
T. Song ◽  
Q. Ma ◽  
X.W. Sun ◽  
Z.J. Liu ◽  
Z.J. Fu ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Equation Of State ◽  
Phase Stability ◽  
First Principles ◽  
First Principles Calculations

The pressure dependence of physical properties of (W2/3Ti1/3)3AlC2 and its counterpart W3AlC2 by first-principles calculations

2017 ◽  
Vol 31 (34) ◽  
pp. 1750326 ◽  
Author(s):  
Yefei Li ◽  
Liang Sun ◽  
Jiandong Xing ◽  
Shengqiang Ma ◽  
Qiaoling Zheng ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Hydrostatic Pressure ◽  
First Principles ◽  
Density Functional ◽  
Elastic Anisotropy ◽  
Debye Model ◽  
Mechanical Anisotropy ◽  
Max Phase ◽  
First Principles Calculations ◽  
Covalent Bonds

First-principles calculations based on density functional theory (DFT) were used to investigate the mechanical properties, elastic anisotropy, electronic structure, optical properties and thermodynamic properties of a new quaternary MAX phase (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] and its counterpart W[Formula: see text]AlC[Formula: see text] under hydrostatic pressure. The results indicate that the volumetric shrinkage of (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] is faster than that of axial shrinkage under hydrostatic pressure. The stress–strain method and Voigt–Reuss–Hill approximation were used to calculate elastic constants and moduli, respectively. These compounds are mechanically stable under hydrostatic pressure. Moreover, the moduli of (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] and W[Formula: see text]AlC[Formula: see text] increase with an increase in pressure. The anisotropic indexes and surface constructions of bulk and Young’s moduli were used to illustrate the mechanical anisotropy under hydrostatic pressure. Electronic structure and optical property of (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] and W[Formula: see text]AlC[Formula: see text] have also been discussed. The results of Debye temperature reveal that the covalent bonds among atoms in (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] may be stronger than that of W3AlC[Formula: see text]. The heat capacity, [Formula: see text]–[Formula: see text], and thermal expansion coefficient of (W[Formula: see text]Ti[Formula: see text])[Formula: see text]AlC[Formula: see text] and W[Formula: see text]AlC[Formula: see text] were discussed in the ranges of 0–30 GPa and 0–2000 K using quasi-harmonic Debye model considering the phonon effects.

Sign in / Sign up

Export Citation Format

Share Document