scholarly journals Mechanical Properties and Thermodynamic Parameters of Sr2 RuO4 and Sr2 RuO2 F2 Compounds under Pressure and Temperature Effects: Voigt–Reuss–Hill Approximations and Debye Model

2021 ◽  
pp. 1-8
Author(s):  
Meryem Ziati ◽  
◽  
Hamid Ez Zahraouy ◽  
Keyword(s):  
Thermodynamic Properties ◽  
Thermodynamic Parameters ◽  
Elastic Constants ◽  
Density Functional ◽  
Mechanical Stability ◽  
Poisson Ratio ◽  
Young Modulus ◽  
Debye Model ◽  
Full Potential ◽  
Pressure And Temperature Effects

We present a first-principles study of the elastic and thermodynamic properties of the Sr2 RuO4 -xFx alloy (x = 0, 2). Computations are carried out using the WIEN2K code based on a non-relativistic full–potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT). The Voigt–Reuss–Hill approximation method is applied to analyze the elastic constants, Poisson ratio, bulk, shear, and Young modulus at zero pressure and temperature using ELASTIC 1.0 software. The Sr2 RuO4 and Sr2 RuO2 F2 tetragonal phases are mechanically stable because the elastic constants satisfy Born’s mechanical stability condition. In addition, we performed a quasi-harmonic Debye model calculation using the GIBBS2 package to predict the thermodynamic properties and their temperature and pressure dependencies. Thermodynamic parameters such as the Gibbs free energy, heat capacity, Grüneisen parameter, and Debye temperature are successfully obtained and discussed

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.

The structure, elastic and thermodynamic properties of Ti2GaC from first-principles calculation

2019 ◽  
Vol 33 (06) ◽  
pp. 1950030 ◽  
Author(s):  
Xiao-Xia Pu ◽  
Xiao-Jiang Long ◽  
Lin Zhang ◽  
Jun Zhu
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constant ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Theoretical Data ◽  
Debye Model ◽  
First Principles Calculation

In this work, the structure, elastic and thermodynamic properties of Ti2GaC at high pressure (P) and high-temperature (T) are studied based on the density functional first-principles. The lattice parameters and elastic constants are well consistent with some theoretical data and experimental results. The elastic constant of Ti2GaC increase monotonously with the increase of pressure (P), which demonstrates the mechanical stability of Ti2GaC at the pressure (P) from 0 to 200 GPa. Mechanical properties including Poisson’s ratio ([Formula: see text]), Young’s modulus (E), shear modulus (G) and bulk modulus (B), which are obtained from elastic constants C[Formula: see text]. The ratio B/G value shows that Ti2GaC is a brittle material, but its enhancing ductility significantly with the elevate of pressure (P). The Grüneisen parameters ([Formula: see text]), thermal expansion coefficient ([Formula: see text]), heat capacity (C[Formula: see text]), elastic constant (C[Formula: see text]), bulk modulus (B), energy (E) and volume (V) with the change of temperature (T) or pressure (P) are calculated within the quasi-harmonic Debye model for pressure (P) and temperatures (T) range in 1600 K and 100 GPa. Besides, densities of states and energy band are also obtained and analyzed in comparison with available theoretical data.

FIRST-PRINCIPLES HIGH-PRESSURE ELASTIC AND THERMODYNAMIC PROPERTIES OF TANTALUM

2011 ◽  
Vol 25 (10) ◽  
pp. 1393-1407 ◽  
Author(s):  
JING-HE WU ◽  
XIAN-LIN ZHAO ◽  
YOU-LIN SONG ◽  
GUO-DONG WU
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
First Principles ◽  
Equations Of State ◽  
Debye Model ◽  
Thermal Expansivity ◽  
Orbital Method ◽  
Full Potential ◽  
Body Centered Cubic ◽  
Theoretical Results

The all-electron full-potential linearized muffin-tin orbital method, by means of quasi-harmonic Debye model, is applied to investigate the elastic constant and thermodynamic properties of body-centered-cubic tantalum (bcc Ta). The calculated elastic constants of bcc Ta at 0 K is consistent with the previous experimental and theoretical results. Our calculations give the correct trends for the pressure dependence of elastic constants. By using the convenient quasi-harmonic Debye model, we refined the thermal equations of state. The thermal expansivity and some other thermal properties agree well with the previous experimental and theoretical results.

scholarly journals Ab initio calculations of structural, elastic, electronic and thermodynamic properties of the cerium filled skutterudite CeRu4P12 under the effect of pressure

2015 ◽  
Vol 33 (4) ◽  
pp. 699-708 ◽  
Author(s):  
Mokhtar Berrahal ◽  
Mohammed Ameri ◽  
Y. Al-Douri ◽  
U. Hashim ◽  
Dinesh Varshney ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Debye Model ◽  
Lattice Parameter ◽  
Full Potential ◽  
Generalized Gradient ◽  
Filled Skutterudite ◽  
Effect Of Pressure ◽  
Lmto Method

AbstractThe paper presents an investigation on crystalline, elastic and electronic structure in addition to the thermodynamic properties for a CeRu4P12 filled skutterudite device by using the full-potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximations (GGA) in the frame of density functional theory (DFT). For this purpose, the structural properties, such as the equilibrium lattice parameter, bulk modulus and pressure derivatives of the bulk modulus, were computed. By using the total energy variation as a function of strain we have determined the independent elastic constants and their pressure dependence. Additionally, the effect of pressure P and temperature T on the lattice parameters, bulk modulus, thermal expansion coefficient, Debye temperature and the heat capacity for CeRu4P12 compound were investigated taking into consideration the quasi-harmonic Debye model.

First-principles study of the structure, elastic constants, electronic and thermodynamic properties of C15 laves phase ZrMo2

2020 ◽  
Vol 34 (18) ◽  
pp. 2050170
Author(s):  
Xianbo Liu ◽  
Jun Zhu
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Debye Model ◽  
State Density ◽  
Electronic Density ◽  
Plane Wave Method ◽  
Electron State Density ◽  
Phonon Spectra ◽  
Theoretical Simulations

The structure, elastic constants and electron state density of ZrMo2 in [Formula: see text]15 phase are investigated by pseudopotential plane-wave method based on density functional theory (DFT). The thermodynamic properties are studied with the quasi-harmonic Debye model. The calculated results are in good agreement with the previous experimental results and theoretical simulations. The calculated phonon spectra and elastic constants show that [Formula: see text]15 phase of ZrMo2 is mechanically stable. Through the analysis of [Formula: see text]/[Formula: see text] value and Poisson’s ratio, [Formula: see text]15 phase of ZrMo2 shows ductility at 0–150 GPa, and it increases with the increment of pressure. We further explore the mechanism of the metallic properties by analyzing the electronic density of states. In addition, Debye temperature, thermal expansion coefficient and heat capacity as a function of pressure and temperature is discussed, respectively.

The structures, phase transition and elastic and thermodynamic properties of ZnS from first-principles calculations

2021 ◽  
pp. 2150143
Author(s):  
Bo Li ◽  
Weiyi Ren
Keyword(s):  
Phase Transition ◽  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Theoretical Data ◽  
Debye Model ◽  
Volume Curve ◽  
Temperature And Pressure

The phase transition of zinc sulfide (ZnS) from Zinc-blende (ZB) to a rocksalt (RS) structure and the elastic, thermodynamic properties of the two structures under high temperature and pressure are investigated by first-principles study based on the pseudo-potential plane-wave density functional theory (DFT) combined with the quasi-harmonic Debye model. The lattice constant [Formula: see text], bulk modulus [Formula: see text] and the pressure derivative of bulk modulus [Formula: see text]’ of the two structures are calculated. The results are in good agreement with experimental results and the other theoretical data. From the energy–volume curve, enthalpy equal principle and mechanical stability criterion, the transition pressures from the ZB to the RS structure are 16.83, 16.96 and 16.61 GPa, respectively. The three results and the experimental values 14.7–18.1, 16 GPa are very close to each other. Then the elastic properties are also calculated under the pressure ranging from 0 to 30 GPa. Finally, through the quasi-harmonic Debye model, the thermodynamic properties dependence of temperature and pressure in the ranges between 0–1600 K and 0–30 GPa are obtained successfully.

scholarly journals Structural, Electronic, Magnetic, Mechanic and Thermodynamic Properties of the Inverse Heusler Alloy Ti2NiIn Under Pressure

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 429 ◽  
Author(s):  
Tie Yang ◽  
Jieting Cao ◽  
Xiaotian Wang
Keyword(s):  
Thermodynamic Properties ◽  
Heusler Alloy ◽  
Density Functional ◽  
Mechanical Stability ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Half Metallicity ◽  
Electronic Band ◽  
Functional Theory ◽  
Valence Electrons

Structural, electronic, magnetic and mechanic properties of the inverse Heusler alloy Ti2NiIn under different pressure are systematically studied with density functional theory (DFT). The equilibrium lattice constant and electronic band structure at null pressure are obtained to be consistent with previous work. Under currently applied static pressure from 0 GPa to 50 GPa, it is found that the half-metallicity of the material is maintained and the total magnetic moment (Mt) is kept at 3 µB, which obeys the Slater–Pauling rule, Mt = Zt − 18, where Zt is the total number of valence electrons. Besides, the effect of the tetragonal distortion was studied and it is found that the magnetic property of Ti2NiIn is almost unchanged. Several mechanical parameters are calculated including three elastic constants, bulk modulus B, Young’s modulus E, and shear modulus S and the mechanical stability is examined accordingly. Furthermore, the thermodynamic properties, such as the heat capacity CV, the thermal expansion coefficient α, the Grüneisen constant γ and the Debye temperature ΘD, are computed by using the quasi-harmonic Debye model within the same pressure range at a series of temperature from 0 to 1500 K. This theoretical study provides detailed information about the inverse Heusler compound Ti2NiIn from different aspects and can further lead some insight on the application of this material.

scholarly journals Elastic, mechanical and thermodynamic properties of zinc blende III-X (X= As, Sb): ab-initio calculations

2019 ◽  
Vol 4 (1) ◽  
pp. 23
Author(s):  
Miloud IBRIR
Keyword(s):  
Thermodynamic Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Local Density ◽  
Potential Method ◽  
Ground State Structure ◽  
Full Potential ◽  
Lattice Constants ◽  
Calculated Stress ◽  
Linear Fit

In this work, density functional theory plane-wave full potential method, with local density approximation (LDA) are used to investigate the structural, mechanical and thermodynamic properties of of zincblende III-X ( X= As, Sb) compends. Comparison of the calculated equilibrium lattice constants and experimental data shows very good agreement. The elastic constants were determined from a linear fit of the calculated stress-strain function according to Hooke’s law. From the elastic constants, the bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio σ, anisotropy factor A, the ratio B/G and the hardness parameter H for zincblende III-X ( X= As, Sb) compound are obtained. Our calculated elastic constants indicate that the ground state structure of III-X ( X= As, Sb) is mechanically stable. The sound velocities and Debye temperature are also predicted from elastic constants.

scholarly journals FP-(L)APW + lo study of mechanical stability and electronic behavior of CoGe in B20 structure

2017 ◽  
Vol 35 (3) ◽  
pp. 548-559 ◽  
Author(s):  
M. A. Timaoui ◽  
H. Bouafia ◽  
B. Sahli ◽  
S. Hiadsi ◽  
B. Abidri ◽  
...  
Keyword(s):  
Density Functional ◽  
Mechanical Stability ◽  
Plane Waves ◽  
Debye Model ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Full Potential ◽  
Metallic Behavior ◽  
Functional Theory ◽  
First Time

AbstractThe aim of this work is a theoretical study of structural, elastic, electronic and thermal properties of CoGe compound in B20 structure using All-electron self-consistent Full Potential Augmented Plane Waves plus local orbital “FP(L)APW + lo” within the framework of Density Functional Theory DFT. GGA-PBEsol is the exchange-correlation potential selected in this work. This choice is motivated by the success of this functional in predicting structural and mechanical properties of solids. The values obtained by the study of structural properties are in very good agreement with those found previously. In this work, the elastic constants have been predicted for the first time and the obtained values confirm the mechanical stability of the CoGe compound in its B20 structure. The electronic part of this work shows that CoGe has metallic behavior with a mixed bonding between cobalt and germanium of covalent-metallic type. The effect of temperature and hydrostatic pressure on the lattice parameter - a0, heat capacity at constant volume - CV, thermal expansion coefficient - α and entropy - S of the CoGe have been studied using Debye model.

Thermodynamic Properties of AlNi Intermetallics under High Pressure

2011 ◽  
Vol 268-270 ◽  
pp. 275-279
Author(s):  
Hai Yan Wang ◽  
Dong Xia Xu ◽  
Jin Bang Yu ◽  
Xu Sheng Li ◽  
Qian Ku Hu
Keyword(s):  
Thermodynamic Properties ◽  
Density Functional ◽  
Linear Thermal Expansion ◽  
Debye Model ◽  
Lattice Parameter ◽  
Relative Volume ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Calculated Lattice Parameter

The thermodynamic properties of AlNi are investigated by the full-potential linearized muffin-tin orbital (FP-LMTO) scheme within the generalized gradient approximation correction (GGA) in the frame of density functional theory. The calculated lattice parameter and bulk modulus are in excellent agreement with the experimental and other calculated results. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the dependences of relative volumeV/V0on pressureP, cell volumeVon temperatureT, linear thermal expansion α and specific heatCVon temperature and pressure are successfully obtained.

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