Cationic and anionic composition-dependent mechanical and thermal properties of zinc-blende specimens under $${\hbox {Mg}}_{x} {\hbox {Zn}}_{1\hbox {-}x} {\hbox {S}}_{y} {\hbox {Se}}_{1\hbox {-}y}$$ quaternary system: calculations with density functional FP-LAPW scheme

2021 ◽  
Vol 94 (1) ◽  
Author(s):  
Debankita Ghosh ◽  
Manish Debbarma ◽  
Sayantika Chanda ◽  
Bimal Debnath ◽  
Rahul Bhattacharjee ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Quaternary System ◽  
Mechanical And Thermal Properties ◽  
Zinc Blende ◽  
Anionic Composition

scholarly journals Structural, elastic, electronic and thermal properties of InAs: A study of functional density

2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Víctor Mendoza-Estrada ◽  
Melissa Romero-Baños ◽  
Viviana Dovale-Farelo ◽  
William López-Pérez ◽  
Álvaro González-García ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Experimental Studies ◽  
Debye Model ◽  
Band Gap Energy ◽  
Functional Theory ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
The Stability ◽  
Experimental Values

In this research, first-principles calculations were carried out within the density functional theory (DFT) framework, using LDA and GGA, in order to study the structural, elastic, electronic and thermal properties of InAs in the zinc-blende structure. The results of the structural properties (a, B0, ) agree with the theoretical and experimental results reported by other authors. Additionally, the elastic properties, the elastic constants (C11, C12 and C44), the anisotropy coefficient (A) and the predicted speeds of the sound ( , , and ) are in agreement with the results reported by other authors. In contrast, the shear modulus (G), the Young's modulus (Y) and the Poisson's ratio (v) show some discrepancy with respect to the experimental values, although, the values obtained are reasonable. On the other hand, it is evident the tendency of the LDA and GGA approaches to underestimate the value of the band-gap energy in semiconductors. The thermal properties (V, , θD yCV) of InAs, calculated using the quasi-harmonic Debye model, are slightly sensitive as the temperature increases. According to the stability criteria and the negative value of the enthalpy of formation, InAs is mechanically and thermodynamically stable. Therefore, this work can be used as a future reference for theoretical and experimental studies based on InAs.

Density functional calculations of elastic and thermal properties of zinc-blende HgSxSe1−x, HgSxTe1−x and HgSexTe1−x ternary alloys

2020 ◽  
Vol 24 ◽  
pp. e00482
Author(s):  
Manish Debbarma ◽  
Subhendu Das ◽  
Bimal Debnath ◽  
Debankita Ghosh ◽  
Sayantika Chanda ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Ternary Alloys ◽  
Zinc Blende

scholarly journals The Effect of Interaction between Nanofillers and Epoxy on Mechanical and Thermal Properties of Nanocomposites: Theoretical Prediction and Experimental Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
S. Khostavan ◽  
M. Fazli ◽  
M. Ghorbanzadeh Ahangari ◽  
Y. Rostamiyan
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Theoretical Study ◽  
Epoxy Polymer ◽  
Epoxy Composite ◽  
Neat Epoxy ◽  
Mechanical And Thermal Properties ◽  
Host Matrix ◽  
Functional Theory ◽  
The Density Functional Theory

Interfacial interaction between host matrix and nanofillers is a determinative parameter on the mechanical and thermal properties of nanocomposites. In this paper, we first investigated interaction between carbon nanotube (CNT) and montmorillonite clay (MMT) absorbing on epoxy surface in a theoretical study based on the density functional theory (DFT) calculations. Results showed the interaction energy of -1.93 and -0.11 eV for MMT/epoxy and CNT/epoxy, respectively. Therefore, the interaction between epoxy polymer and MMT is of the chemisorptions type, while epoxy physically interacts with CNT. In addition, thermal and mechanical analyses were conducted on nanocomposites. In DSC analysis the glass transition temperature which was 70°C in neat epoxy composite showed an improvement to about 90°C in MMT nanocomposites while it was about 70°C for CNT nanocomposites. Finally, mechanical properties were investigated and MMT nanocomposite showed a change in compressive strength which increased from 52.60 Mpa to 72.07 and 92.98 Mpa in CNT and MMT nanocomposites, respectively. Also tensile strength improved to the value of 1250.69 Mpa MMT nanocomposites while it was about 890 Mpa in both CNT nanocomposite and neat epoxy composite which corresponds to the calculation result prediction.

scholarly journals Mechanical and Thermal Properties of Low-Density Al20+xCr20-xMo20-yTi20V20+y Alloys

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 278 ◽  
Author(s):  
Uttam Bhandari ◽  
Congyan Zhang ◽  
Shizhong Yang
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Cell Model ◽  
High Hardness ◽  
Dft Method ◽  
Mechanical And Thermal Properties ◽  
Low Density ◽  
High Entropy ◽  
Bcc Structure ◽  
Temperature Application

Refractory high-entropy alloys (RHEAs) Al20+xCr20-xMo20-yTi20V20+y ((x, y) = (0, 0), (0, 10), and (10, 15)) were computationally studied to obtain a low density and a better mechanical property. The density functional theory (DFT) method was employed to compute the structural and mechanical properties of the alloys, based on a large unit cell model of randomly distributed elements. Debye–Grüneisen theory was used to study the thermal properties of Al20+xCr20-xMo20-yTi20V20+y. The phase diagram calculation shows that all three RHEAs have a single body-centered cubic (BCC) structure at high temperatures ranging from 1000 K to 2000 K. The RHEA Al30Cr10Mo5Ti20V35 has shown a low density of 5.16 g/cm3 and a hardness of 5.56 GPa. The studied RHEAs could be potential candidates for high-temperature application materials where high hardness, ductility, and low density are required.

Effect of Ce Substitution on Mechanical and Thermal Properties of Tetragonal YSZ: First-Principles Calculations

2015 ◽  
Vol 1120-1121 ◽  
pp. 73-84
Author(s):  
Lei Jin ◽  
Pei Zhong Li ◽  
Guo Dong Zhou ◽  
Wei Gao ◽  
Jiang Ning Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Sound Velocity ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Young's Modulus ◽  
Mechanical And Thermal Properties ◽  
Ce Substitution

The effect of impurity Ce on the mechanical and thermal properties of tetragonal ZrO2 stabilized by rare earth element Y (YSZ) have been studied using first principles density functional theory within generalized gradient approximation (GGA) for the exchange correlation potential. The predicted elastic constants indicate that YSZ and Ce doped YSZ (CeYSZ) are mechanically stable structures. And then the numerical estimates of bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, sound velocity and minimum thermal conductivity were performed using the calculated elastic constants and analyzed for the first time. The values of sound velocity from different orientations are also reported. The agreement between the results of the available experiments and our calculations was satisfactory. Our calculated results indicate that Young’s modulus, hardness, mean sound velocity and minimum thermal conductivity of YSZ can be decreased by Ce substitution. The reasons are from the “softened” Ce-O bond strength using bond population and relative volume change under external hydrostatic pressure. Chemical bonding nature was also analyzed from the density of states and electron density difference.

Electronic structure, elastic and thermal properties of semiconductor GaX (X = N, P, As, Sb) with zinc blende from first-principles calculation

2014 ◽  
Vol 28 (27) ◽  
pp. 1450183 ◽  
Author(s):  
Bingcheng Luo ◽  
Xiaowen Wu ◽  
Guowu Li
Keyword(s):  
Thermal Properties ◽  
Band Structure ◽  
Density Of States ◽  
Density Functional ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Zinc Blende ◽  
Direct Band ◽  
Structure Density ◽  
Potential Methods

The band structure, density of states, elastic properties and thermal properties of semiconductor GaX (X = N , P , As , Sb ) with zinc blende were calculated by using the first principle plane-wave pseudo-potential methods based on density functional theory (DFT). The band structure and density of states for GaN , GaP , GaAs and GaSb show that GaX compounds are semiconductors with a direct band gap of 1.542, 1.445, 0.34 and 0.257 eV, respectively. The elastic constants and modulus are calculated showing that GaX are mechanically stable and GaN has the largest modulus. The anisotropy factor, internal-strain parameter, shear to bulk modulus and Poisson's ratio are also calculated indicating that GaX exhibit a brittle, anisotropic and plastic character. The dependencies of the Debye temperature, heat capacity, enthalpy, the entropy and free energy on temperature are also investigated. Comparisons with the available experiment and other theoretical calculation show reasonable agreement.

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