Phase transition and thermodynamic properties of beryllium telluride under high pressure

A theoretical investigation on structural, dynamical, phase diagram and thermodynamic properties of beryllium telluride (BeTe) under high pressure and temperature is presented in the framework of density functional theory. The calculated structural parameters of BeTe in both zinc blende (ZB) and nickel arsenide (NiAs) structures are in reasonable agreement with available experimental data and previous theoretical work. The phonon dispersion relations, dielectric tensor and Born effective charge are investigated within the density functional perturbation theory (DFPT). The investigation of the phase diagram indicated that the NiAs structure BeTe becomes stable at high pressure and temperature. Based on the quasiharmonic Debye model, the pressure and temperature dependences of bulk modulus, Grüneisen parameter, Debye temperature, specific heat and thermal expansion coefficient are all successfully obtained. We hope that the theoretical results reported here can give more insight into the structural and thermodynamic properties of other semiconductors at high temperature and pressure.

Download Full-text

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

International Journal of Modern Physics B ◽

10.1142/s021797921750254x ◽

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.

Download Full-text

The mechanical and thermodynamic properties of ZrAl2 under pressure from first-principles investigation

International Journal of Modern Physics C ◽

10.1142/s0129183116500017 ◽

2016 ◽

Vol 27 (01) ◽

pp. 1650001

Author(s):

Ning Wei ◽

Xuefei Wang ◽

Xuzhong Zuo

Keyword(s):

Heat Capacity ◽

High Pressure ◽

Thermodynamic Properties ◽

Debye Temperature ◽

First Principles ◽

Density Functional ◽

Applied Pressure ◽

Debye Model ◽

Effect Of Temperature ◽

Expansion Formula

The mechanical and thermodynamic properties of ZrAl2 alloy under high pressure are investigated by first-principles based on the density functional theory. Due to all the elastic constants of ZrAl2 alloy satisfy generalized stabilities criteria, ZrAl2 is mechanically stable under pressure up to 100[Formula: see text]GPa. By analyzing the value of B/G and Poisson’s ratio [Formula: see text] which are correlated with the ductility and brittleness of material, we found that ZrAl2 belongs to brittle material at pressure of 0–70[Formula: see text]GPa and will change from brittleness to ductility at 70[Formula: see text]GPa. Combining with high bulk modulus B and shear modulus G, the mechanical of properties will be improved under high pressure. Moreover, the thermodynamic properties, such as the Debye temperature [Formula: see text], heat capacity [Formula: see text] and thermal expansion [Formula: see text], are discussed using the quasi-harmonic Debye model. We noted that the Debye temperature [Formula: see text] is mainly dependent on the pressure and the effect of temperature on the heat capacity [Formula: see text] is more important than the applied pressure.

Download Full-text

Phonon, elastic and thermodynamic properties of L12 phase Rh3Zr under pressure from first-principles

International Journal of Modern Physics C ◽

10.1142/s012918311750098x ◽

2017 ◽

Vol 28 (07) ◽

pp. 1750098

Author(s):

Leini Wang ◽

Zhang Jian ◽

Wei Ning

Keyword(s):

High Pressure ◽

Thermodynamic Properties ◽

Elastic Constants ◽

Density Functional ◽

Pressure Range ◽

Harmonic Approximation ◽

Debye Model ◽

Theory Approach ◽

Wide Pressure Range ◽

The Stability

The phonon, elastic and thermodynamic properties of L12 phase Rh3Zr have been investigated by density functional theory approach combining with quasi-harmonic approximation model. The relaxed lattice parameters of L12 phase Rh3Zr at zero pressure are in good agreement with the experiment. To judge the stability of L12 phase Rh3Zr under high pressure, the phonon band structure has been studied. The results show that L12 phase Rh3Zr possesses dynamical stability in the pressure range from 0[Formula: see text]GPa to 80[Formula: see text]GPa due to the absence of imaginary frequencies. The pressure dependences of elastic constants [Formula: see text] have been analyzed. All the elastic constants of Rh3Zr in a wide pressure range (0–80[Formula: see text]GPa) meet general mechanical conditions, suggesting that L12 phase Rh3Zr is mechanically stable under pressure up to 80[Formula: see text]GPa. L12 phase Rh3Zr exhibits ductility under high pressure and the pressure can improve the ductility from the results of the value of [Formula: see text] and Poisson’s ratio [Formula: see text]. Hence, it is obvious that the mechanical properties of Rh3Zr can be improved under high pressure. Moreover, we have obtained the thermodynamic properties using the quasi-harmonic Debye model. We note that the effect of the temperature on the Debye temperature [Formula: see text] is smaller than that of the pressure. We believe that our result will be a good guidance to future works and applications.

Download Full-text

First-principles investigations on the elastic and thermodynamic properties of cubic ZrO2 under high pressure

International Journal of Modern Physics C ◽

10.1142/s0129183115500564 ◽

2015 ◽

Vol 26 (05) ◽

pp. 1550056 ◽

Cited By ~ 2

Author(s):

Ning Wei ◽

Xiaoli Zhang ◽

Chuanguo Zhang ◽

Songjun Hou ◽

Z. Zeng

Keyword(s):

High Pressure ◽

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

Debye Model ◽

Pressure Effects ◽

Ductile Material ◽

Generalized Gradient ◽

Functional Theory ◽

Resistance To Deformation

We have investigated the elastic and thermodynamic properties of ZrO 2 under pressure up to 120 Gpa by the plane wave pseudopotential density functional theory with the generalized gradient approximation (GGA) method. The elastic constants of ZrO 2 are calculated and meet the generalized stability criteria, suggesting that ZrO 2 is mechanically stable within this pressure range. The pressure effects on the elastic properties reveal that the elastic modulus B, shear modulus G and Young's modulus Y increase linearly with the pressure increasing, implying that the resistance to deformation is enhanced. In addition, by analyzing the Poisson's ratio ν and the value of B/G, we notice that ZrO 2 is regarded as being a ductile material under high pressure and the ductility can be improved by the pressure increasing. Then, we employ the quasi-harmonic Debye model considering the phononic effects to obtain the thermodynamic properties of ZrO 2. Debye temperature ΘD, thermal expansion coefficient α, heat capacity Cp and Grüneisen parameter γ are systematically explored at pressure of 0–80 Gpa and temperature of 0–1000 K. Our results have provided fundamental facts and evidences for further experimental and theoretical researches.

Download Full-text

Theoretical Prediction on the Structural, Electronic, Mechanical, and Thermodynamic Properties of TaSi2 with a C40 Structure Under Pressure

Zeitschrift für Naturforschung A ◽

10.1515/zna-2018-0433 ◽

2019 ◽

Vol 74 (4) ◽

pp. 353-361 ◽

Cited By ~ 1

Author(s):

HuaJun Zhu ◽

Tao Yang ◽

Yang Zhou ◽

SuDong Hua ◽

JinWen Yang

Keyword(s):

Thermodynamic Properties ◽

Elastic Constants ◽

Electronic Structures ◽

Density Functional ◽

Theoretical Calculations ◽

Structural Parameters ◽

Applied Pressure ◽

Three Dimensional ◽

Debye Model ◽

Experimental Findings

AbstractThe structural parameters, electronic structures, and mechanical and thermodynamic properties of TaSi2 under different pressures have been completely explored by a combination of density functional theory and quasi-harmonic Debye model. Results show that our computed structural parameters and elastic constants are in consistency with available experimental findings and previous theoretical calculations. The electronic structures of TaSi2 under different pressures including band structures and density of states are reported. It turns out that TaSi2 should be metallic. The elastic constants Cij, bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio ν, B/G, Debye temperature θ, and wave velocities under pressures are also evaluated successfully. The calculated Cij obeys the Born–Huang stability criterion, which demonstrates that TaSi2 is mechanically stable under different pressures. More interestingly, the three-dimensional surface constructions and projections of E and B under different pressures are also systematically evaluated. With the increase of applied pressure, TaSi2 exhibits subtle anisotropy under zero pressure, and the anisotropy strengthened. Finally, the dependence of the thermodynamic properties on pressure/temperature is obtained and analyzed for the first time.

Download Full-text

Pressure effect of the mechanical, electronics and thermodynamic properties of Mg–B compounds A first-principles investigations

Scientific Reports ◽

10.1038/s41598-021-85654-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

GuoWei Zhang ◽

Chao Xu ◽

MingJie Wang ◽

Ying Dong ◽

FengEr Sun ◽

...

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Boron Content ◽

Structural Parameters ◽

Debye Model ◽

Total Density ◽

First Principle ◽

Volume Deformation ◽

Temperature And Pressure ◽

Total Density Of States

AbstractFirst principle calculations were performed to investigate the structural, mechanical, electronic properties, and thermodynamic properties of three binary Mg–B compounds under pressure, by using the first principle method. The results implied that the structural parameters and the mechanical properties of the Mg–B compounds without pressure are well matched with the obtainable theoretically simulated values and experimental data. The obtained pressure–volume and energy–volume revealed that the three Mg–B compounds were mechanically stable, and the volume variation decreases with an increase in the boron content. The shear and volume deformation resistance indicated that the elastic constant Cij and bulk modulus B increased when the pressure increased up to 40 GPa, and that MgB7 had the strongest capacity to resist shear and volume deformation at zero pressure, which indicated the highest hardness. Meanwhile, MgB4 exhibited a ductility transformation behaviour at 30 GPa, and MgB2 and MgB7 displayed a brittle nature under all the considered pressure conditions. The anisotropy of the three Mg–B compounds under pressure were arranged as follows: MgB4 > MgB2 > MgB7. Moreover, the total density of states varied slightly and decreased with an increase in the pressure. The Debye temperature ΘD of the Mg–B compounds gradually increased with an increase in the pressure and the boron content. The temperature and pressure dependence of the heat capacity and the thermal expansion coefficient α were both obtained on the basis of Debye model under increased pressure from 0 to 40 GPa and increased temperatures. This paper brings a convenient understanding of the magnesium–boron alloys.

Download Full-text

Structural, elastic and thermodynamic properties of A15-type compounds V3X (X = Ir, Pt and Au) from first-principles calculations

Modern Physics Letters B ◽

10.1142/s0217984916504145 ◽

2016 ◽

Vol 30 (35) ◽

pp. 1650414 ◽

Cited By ~ 6

Author(s):

Mingliang Wang ◽

Zhe Chen ◽

Dong Chen ◽

Cunjuan Xia ◽

Yi Wu

Keyword(s):

Thermodynamic Properties ◽

Debye Temperature ◽

First Principles ◽

Density Functional ◽

Coefficient Of Thermal Expansion ◽

Local Density ◽

Debye Model ◽

First Principles Calculations ◽

Generalized Gradient ◽

Experimental Values

The structural, elastic and thermodynamic properties of the A15 structure V3Ir, V3Pt and V3Au were studied using first-principles calculations based on the density functional theory (DFT) within generalized gradient approximation (GGA) and local density approximation (LDA) methods. The results have shown that both GGA and LDA methods can process the structural optimization in good agreement with the available experimental parameters in the compounds. Furthermore, the elastic properties and Debye temperatures estimated by LDA method are typically larger than the GGA methods. However, the GGA methods can make better prediction with the experimental values of Debye temperature in V3Ir, V3Pt and V3Au, signifying the precision of the calculating work. Based on the E–V data derived from the GGA method, the variations of the Debye temperature, coefficient of thermal expansion and heat capacity under pressure ranging from 0 GPa to 50 GPa and at temperature ranging from 0 K to 1500 K were obtained and analyzed for all compounds using the quasi-harmonic Debye model.

Download Full-text

DFT study of electronic and thermodynamic properties of gold-rich intermetallic compounds, Ce2Au2Cd and CeAu4Cd2

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-7955 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Jyoti Sagar ◽

Reetu Singh ◽

Vijay Kumar ◽

Sanjay Kumar ◽

Manish P. Singh ◽

...

Keyword(s):

Thermodynamic Properties ◽

Mechanical Strength ◽

Intermetallic Compounds ◽

Density Functional ◽

Electronic Band Structure ◽

Debye Model ◽

Effect Of Temperature ◽

Mechanical Resistance ◽

Electronic Band ◽

High Mechanical Strength

Abstract Gold-rich rare earth intermetallic compounds (viz. Ce2Au2Cd and CeAu4Cd2) show unusual magnetic and physical properties, and they have extensive applications in electronic and mechanical industries due to their good electronic and thermal behavior with high mechanical strength. In the present research article, to take full advantage of technological importance of these materials, we have investigated the structural, electronic and thermodynamic properties of Ce2Au2Cd and CeAu4Cd2 ternary intermetallic compounds using density functional theory (DFT). The electronic band structure and density of state calculations show that Ce-f orbital electrons provide metallic character to both the compounds with strong hybridization of Au-p and Cd-p orbitals at the Fermi level. The effect of temperature has been studied on the various thermodynamic parameters using the quasi-harmonic Debye model. Thermodynamic properties show that CeAu4Cd2 compound has larger mechanical resistance (or high mechanical strength or hardness) and smaller randomness compared to Ce2Au2Cd with respect to temperature.

Download Full-text

Strain Conditions for the Inverse Heusler Type Fully Compensated Spin-Gapless Semiconductor Ti2MnAl: A First-Principles Study

Materials ◽

10.3390/ma11112091 ◽

2018 ◽

Vol 11 (11) ◽

pp. 2091 ◽

Cited By ~ 13

Author(s):

Tie Yang ◽

Liyu Hao ◽

Rabah Khenata ◽

Xiaotian Wang

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

Theoretical Study ◽

Debye Model ◽

Pressure Effects ◽

First Principles Calculation ◽

Strain Condition ◽

Functional Theory ◽

Future Work

In this work, we systematically studied the structural, electronic, magnetic, mechanical and thermodynamic properties of the fully compensated spin-gapless inverse Heusler Ti2MnAl compound under pressure strain condition by applying the first-principles calculation based on density functional theory and the quasi-harmonic Debye model. The obtained structural, electronic and magnetic behaviors without pressure are well consistent with previous studies. It is found that the spin-gapless characteristic is destroyed at 20 GPa and then restored with further increase in pressure. While, the fully compensated ferromagnetism shows a better resistance against the pressure up to 30 GPa and then becomes to non-magnetism at higher pressure. Tetragonal distortion has also been investigated and it is found the spin-gapless property is only destroyed when c/a is less than 1 at 95% volume. Three independent elastic constants and various moduli have been calculated and they all show increasing tendency with pressure increase. Additionally, the pressure effects on the thermodynamic properties under different temperature have been studied, including the normalized volume, thermal expansion coefficient, heat capacity at constant volume, Grüneisen constant and Debye temperature. Overall, this theoretical study presents a detailed analysis of the physical properties’ variation under strain condition from different aspects on Ti2MnAl and, thus, can provide a helpful reference for the future work and even inspire some new studies and lead to some insight on the application of this material.

Download Full-text

Thermodynamic Properties of CaSiO3 Perovskite at High Pressure and High Temperature

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-5-615 ◽

2009 ◽

Vol 64 (5-6) ◽

pp. 399-404 ◽

Cited By ~ 1

Author(s):

Zi-Jiang Liu ◽

Xiao-Ming Tan ◽

Yuan Guo ◽

Xiao-Ping Zheng ◽

Wen-Zhao Wu

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Local Density ◽

Harmonic Approximation ◽

Debye Model ◽

Functional Theory ◽

Casio3 Perovskite ◽

First Time

The thermodynamic properties of tetragonal CaSiO3 perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines the ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state is in excellent agreement with the observed values at ambient condition. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

Download Full-text