scholarly journals Thermal properties of cubic zincblende thallium-phosphide from quasi-harmonic Debye model approximation

2017 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Salah Daoud
Keyword(s):  
High Pressure ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Unit Cell Volume ◽  
Theoretical Data ◽  
Debye Model ◽  
Zero Temperature ◽  
Isothermal Bulk Modulus ◽  
Model Approximation ◽  
First Order

The thermal properties of cubic zincblende (B3) thallium - phosphide (TlP) compound under high pressure up to 12 GPa have been studied using the quasi-harmonic Debye model approximation. The relative unit cell volume, the isothermal bulk modulus, the first order derivative isothermal bulk modulus, the Debye temperature and the Grüneisen parameter are studied at zero-temperature and at standard ambient temperature (298 K) respectively. Our obtained values of the different previous quantities are in general in agreement compared to other theoretical data of the literature.

First-principles study on structural, elastic and thermal properties of γ-TiAl and α2-Ti3Al phases in TiAl-based alloy under high pressure

2017 ◽  
Vol 31 (11) ◽  
pp. 1750079 ◽  
Author(s):  
Chaoyan Zhang ◽  
Hua Hou ◽  
Yuhong Zhao ◽  
Xiaomin Yang ◽  
Yaqiong Guo
Keyword(s):  
High Pressure ◽  
Thermal Properties ◽  
Density Functional ◽  
Theoretical Data ◽  
Debye Model ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Two Phases ◽  
Calculated Equilibrium ◽  
Good Agreement

The structural, elastic and thermal properties of [Formula: see text]-TiAl and [Formula: see text]-Ti3Al phases in the TiAl-based alloy under pressure were reported using CASTEP program based on the density functional theory. The calculated equilibrium parameters and elastic constants are in good agreement with experimental and the available theoretical data. The results indicate that under the same pressure, the [Formula: see text] phase in the direction along [Formula: see text]-axis is easier to be compressed than the [Formula: see text] phase, while the compression along [Formula: see text]-axis of [Formula: see text] phase is larger than that of [Formula: see text] phase; when the pressure is below 20 GPa, both the two phases are elastically stable, but the [Formula: see text] phase have higher shear modulus and Young’s modulus, and the [Formula: see text] phase has better ductility and plasticity. Debye temperature, bulk modulus, thermal expansion coefficient and heat capacity of the [Formula: see text] phase and [Formula: see text] phase under high pressure and high temperature were also successfully calculated and compared using the quasi-harmonic Debye model in the present work.

scholarly journals Elastic Behaviour of Diborides Under High Pressure

2009 ◽  
Vol 1 (2) ◽  
pp. 275-280
Author(s):  
Seema Gupta ◽  
S. C. Goyal
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Statistical Model ◽  
Bulk Modulus ◽  
Electron Gas ◽  
Elastic Behaviour ◽  
Pressure Derivative ◽  
First Order ◽  
Elastic Data ◽  
Quantum Statistical

The present study deals with the elastic behaviour of diborides (BeB2, MgB2 and NbB2) under high pressure with the help of equation of state (EOS) using the elastic data reported by Islam et al. It is concluded that EOS, which are based either on quantum statistical model or  pseduopotential model, only are capable of explaining high pressure behaviour of the solids under study.  Moreover the value of first order pressure derivative of bulk modulus at infinite pressure (Kinfinity) is greater than 5/3 and thus the diborides under study do not behave as Thomas-Fermi electron gas under high compression. Keywords: Equation of state; High Pressure; Diborides. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1189 

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.

High-pressure and high-temperature bulk modulus of cubic fluorite-type MgF2 from quasi-harmonic Debye model

2011 ◽  
Vol 151 (21) ◽  
pp. 1507-1510 ◽  
Author(s):  
X.W. Sun ◽  
T. Song ◽  
Z.J. Liu ◽  
C.R. Zhang ◽  
J.H. Tian ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Bulk Modulus ◽  
Debye Model ◽  
Fluorite Type

Thermodynamic Properties of Nb4AlC3

2013 ◽  
Vol 456 ◽  
pp. 442-446
Author(s):  
Ai Ling Ding ◽  
Wen Bin Yu ◽  
Chun Mei Li ◽  
Zhi Qian Chen
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Local Density ◽  
Density Functional Theory Method ◽  
Debye Model ◽  
Relative Volume ◽  
Zero Temperature ◽  
Functional Theory ◽  
Entropy Parameter

We use ab initio plane-wave pseudopotential density functional theory method within local density approximation (LDA) to investigate the thermodynamic properties of Nb4AlC3 under high pressure (0-100 GPa) and high temperature (0-3000 K). Through the quasi-harmonic Debye model, we investigate the thermodynamic properties of Nb4AlC3.The variation of the relative volume, bulk modulus, entropy parameter S, the thermal expansion coefficient α , the heat capacity and the Gruneisen parameter γ with pressure P and temperature T, and many other thermodynamic parameters of Nb4AlC3 are obtained systematically. The bulk modulus of Nb4AlC3 is 250 GPa under zero temperature and zero pressure.

Equation of state and some other properties of rock-salt AlN

2018 ◽  
Vol 6 (1) ◽  
pp. 49
Author(s):  
Salah Daoud ◽  
Rabie Mezouar ◽  
Abdelfateh Benmakhlouf
Keyword(s):  
Heat Capacity ◽  
High Pressure ◽  
Equation Of State ◽  
Bulk Modulus ◽  
Temperature Dependence ◽  
Rock Salt ◽  
Thermophysical Properties ◽  
Constant Pressure ◽  
Isothermal Bulk Modulus ◽  
Pressure Derivative

The object of the present work is to study the equation of state (EOS) and the temperature dependence of the vibrational constant pressure heat capacity, the adiabatic bulk modulus Bs and the pressure derivative of the isothermal bulk modulus of cubic rock-salt Aluminum nitride under high pressure up to 100 GPa. In addition, the isothermal bulk modulus and the Debye temperature θD versus pressure at 1800 K are presented. Some structural and thermophysical properties used here are taken from our previous paper published in J. Electron. Mater. (2018) DOI: 10.1007/s11664-018-6169-x. The results obtained are analyzed and compared with other data of the literature.  

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 calculations of structural, electronic and thermal properties of Zn1−x MgxS ternary alloys

Open Physics ◽  
2014 ◽  
Vol 12 (1) ◽  
Author(s):  
Samia Lamraoui ◽  
Rachid Bensalem ◽  
Khadidja Hacini ◽  
Hocine Meradji ◽  
Sebti Ghemid ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Small Deviation ◽  
Experimental Studies ◽  
Theoretical Data ◽  
Debye Model ◽  
Ternary Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Vegard’S Law

AbstractStructural, electronic and thermal properties of Zn1−x MgxS ternary alloys are studied by using the full potential-linearized augmented plane wave method (FP-LAPW) within the density functional theory (DFT). The Wu-Cohen generalized gradient approximation (WC-GGA) is used in this approach for the exchangecorrelation potential. Moreover, the modified Becke-Johnson approximation (mBJ) is adopted for band structure calculations. The dependence of the lattice constant, bulk modulus and band gap on the composition x showed that the first exhibits a small deviation from the Vegard’s law, whereas, a marginal deviation of the second from linear concentration dependence (LCD). The bowing of the fundamental gap versus composition predicted by our calculations agrees well with the available theoretical data. The microscopic origins of the gap bowing are explained by using the approach of Zunger and co-workers. Thermal effects on some macroscopic properties of Zn1−x MgxS alloys are also investigated using the quasi-harmonic Debye model, in which the phononic effects are considered. As, this is the first quantitative theoretical prediction of the thermal properties of Zn1−x MgxS alloys, no other calculated results and furthermore no experimental studies are available for comparison.

Isothermal bulk modulus and its first pressure derivative of NaCl at high pressure and high temperature

2012 ◽  
Vol 21 (3) ◽  
pp. 037103 ◽  
Author(s):  
Ting Song ◽  
Xiao-Wei Sun ◽  
Zi-Jiang Liu ◽  
Jian-Feng Li ◽  
Jun-Hong Tian
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Bulk Modulus ◽  
Isothermal Bulk Modulus ◽  
Pressure Derivative
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