First-principle study on ScAl3C3-type LaCd3P3 phases under high pressure

2020 ◽  
Vol 34 (29) ◽  
pp. 2050347
Author(s):  
Yufen Ren ◽  
Shiquan Feng ◽  
Chaosheng Yuan ◽  
Xuerui Cheng ◽  
Zuo Li
Keyword(s):  
High Pressure ◽  
Optical Properties ◽  
Thermal Properties ◽  
First Principles ◽  
High Pressures ◽  
Mechanical Stability ◽  
Pressure Effect ◽  
First Principle ◽  
First Principles Calculations ◽  
Debye Temperatures

Using first-principles calculations, we investigate the structural, electronic, thermal and optical properties of hexagonal ScAl3C3-type structure LaCd3P3 under high pressure. By calculating elastic constant, the mechanical stability of LaCd3P3 at high pressures was discussed. Then, by calculating the band gap and density of states, the pressure effect on electronic properties of LaCd3P3 was discussed. By calculating longitudinal, transverse sound, mean sound velocities, and the Debye temperatures at different pressures, the effect of pressure on thermal properties of LaCd3P3 was investigated. What is more, the dielectric function [Formula: see text] and reflectivity [Formula: see text] were calculated to explore the change of optical properties of LaCd3P3 under high pressure.

scholarly journals First-principles study of SnO under high pressure

2016 ◽  
Vol 30 (31) ◽  
pp. 1650228 ◽  
Author(s):  
M. A. Ali ◽  
A. K. M. A. Islam ◽  
N. Jahan ◽  
S. Karimunnesa
Keyword(s):  
High Pressure ◽  
Optical Properties ◽  
First Principles ◽  
High Pressures ◽  
Mechanical Stability ◽  
Generalized Gradient ◽  
First Principles Study ◽  
Anisotropic Factor ◽  
High Anisotropy ◽  
Very High

This paper reports the first-principles study of SnO under high pressure within the generalized gradient approximation (GGA). We have calculated the structural, elastic, electronic and optical properties of SnO. The elastic properties such as the elastic constants [Formula: see text], bulk modulus, shear modulus, Young’s modulus, anisotropic factor, Pugh’s ratio and Poisson’s ratio are calculated and analyzed. Mechanical stability of SnO at all pressures is confirmed using the Born’s stability conditions in terms of [Formula: see text]. It is also found that SnO exhibits very high anisotropy. The energy band structure and density of states are also calculated and analyzed. The results show the semiconducting and metallic properties at zero and high pressures, respectively. Furthermore, the optical properties are also calculated. All the results are compared with those of SnO where available but most of the results at high pressure are not compared due to the unavailability of results.

High pressure effect on the electronic structure and thermoelectric properties of BiCuSeO: first-principles calculations

RSC Advances ◽  
2014 ◽  
Vol 4 (97) ◽  
pp. 54819-54825 ◽  
Author(s):  
Daifeng Zou ◽  
Yunya Liu ◽  
Shuhong Xie ◽  
Jianguo Lin ◽  
Hairong Zheng ◽  
...  
Keyword(s):  
High Pressure ◽  
Electronic Structure ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Pressure Effect ◽  
First Principles Calculations ◽  
High Pressure Effect

High-pressure and thermal properties of γ-Mg2SiO4 from first-principles calculations

2002 ◽  
Vol 117 (7) ◽  
pp. 3340-3344 ◽  
Author(s):  
P. Piekarz ◽  
P. T. Jochym ◽  
K. Parlinski ◽  
J. Łażewski
Keyword(s):  
High Pressure ◽  
Thermal Properties ◽  
First Principles ◽  
First Principles Calculations

First-principles study of the phonon, mechanical and thermodynamic properties of B2-phase AlY under high pressures

2017 ◽  
Vol 31 (32) ◽  
pp. 1750254
Author(s):  
Leini Wang ◽  
Zhang Jian ◽  
Wei Ning
Keyword(s):  
High Pressure ◽  
Thermodynamic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
High Pressures ◽  
Mechanical Stability ◽  
Debye Model ◽  
Functional Theory ◽  
B2 Phase

We have investigated the phonon, mechanical and thermodynamic properties of B2-phase AlY under high pressure by performing density functional theory (DFT). The result of phonon band structure shows B2-phase AlY exhibits dynamical stability. Then, the elastic properties of AlY under high pressure have been discussed. The elastic constants of AlY increase monotonically with the increase of the pressure and all the elastic constants meet the mechanical stability standard under high pressure. By analyzing the Poisson’s ratio [Formula: see text] and the value of B/G of AlY, we first predicted that AlY undergoes transformation from brittleness to ductility at 30 GPa and high pressure can improve the ductility. To obtain the thermodynamic properties of B2-phase AlY, the quasi-harmonic Debye model has been employed. Debye temperature [Formula: see text], thermal expansion coefficient [Formula: see text], heat capacity C[Formula: see text] and Grüneisen parameter [Formula: see text] of B2-phase AlY are systematically explored at pressure of 0–75 GPa and temperature of 0–700 K.

First-Principles Calculations of the Mechanical and Elastic Properties of 2Hc- and 2Ha-WS2/CrS2 Under Pressure

2016 ◽  
Vol 71 (6) ◽  
pp. 517-524 ◽  
Author(s):  
Hua-Long Jiang ◽  
Song-Hao Jia ◽  
Da-Wei Zhou ◽  
Chun-Ying Pu ◽  
Fei-Wu Zhang ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Elastic Properties ◽  
First Principles ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
First Principles Calculations ◽  
Stability Criteria ◽  
Poisson Coefficient ◽  
Debye Temperatures ◽  
Two Phases

AbstractBy utilizing the first-principles method, the pressure-induced effects on phase transition, mechanical stability, and elastic properties of WS2/CrS2 are investigated in the pressure range from 0 to 80 GPa. Transitions from 2Hc to 2Ha for WS2 and CrS2 are found to occur at 17.5 and 25 GPa, respectively. It is found that both 2Ha and 2Hc phases of WS2 and CrS2 meet the mechanical stability criteria up to 80 GPa, suggesting that those structures are mechanically stable. The bulk and shear modulus anisotropy of the two phases of WS2 and CrS2 decrease rapidly under pressure and, finally, trend to isotropy. With increasing pressure, the elastic moduli (Y, B, and G), sound velocities (vs, vp, vm), and Debye temperatures (Θ) of 2Ha and 2Hc of WS2 and CrS2 increase monotonously. Moreover, the Debye temperature (Θ) of 2Hc phase is higher than that of 2Ha phase for both WS2 and CrS2. The bulk, shear, and Young’s modulus, Poisson coefficient, and brittle/ductile behaviour are estimated. The percentages of anisotropy in compressibility and shear and the ratio of bulk to shear modulus (B/G) are also studied.

Theoretical studies of structural stability at high pressure

1995 ◽  
Vol 73 (5-6) ◽  
pp. 253-257 ◽  
Author(s):  
John S. Tse ◽  
Dennis D. Klug
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
First Principles ◽  
High Pressures ◽  
Structural Phase ◽  
Md Simulations ◽  
Quantum Molecular Dynamics ◽  
First Principles Calculations ◽  
Quantum Mechanical Effects ◽  
Structural Memory

Theoretical methods are indispensible for the study of matter at high pressure. In the last decade the development of accurate intermolecular potentials and the methodologies in classical molecular dynamics (MD) simulations have greatly facililated the applications of these methods to the study of structural phase transformamtions of solids at high pressures. More recently, it has been possible to incorporate quantum mechanical effects into MD calculations. This method eliminates a great deal of empiricism. These first principles calculations have not only reproduced the experimental results for phase transformations but also provided detailed mechanisms and in some cases predicted new structures that may be found at high pressures. The success of MD calculations is illustrated through a review of our studies of pressure-induced amorphization and phase transitions in SiO2 and TiO2, and the structural memory effect in several materials. Current applications using quantum molecular dynamics on ice are discussed.

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