First-Principle Studies Al-Fe-Ti-Cr-Zn-Cu High Entropy Solid Solutions with Pressure-Induced

2014 ◽  
Vol 809-810 ◽  
pp. 333-347 ◽  
Author(s):  
Lan Xin Wang ◽  
Shan Yao ◽  
Bin Wen
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Solid Solutions ◽  
Density Functional ◽  
Mechanical Stability ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
High Entropy ◽  
Bcc Structure ◽  
Fcc Structure

The structural properties, elastic properties, mechanical stability, and phase transition of equiatomic Al-Fe-Ti-Cr-Zn-Cu high entropy solid solutions from binary (Al-Fe) to hexanary (Al-Fe-Ti-Cr-Zn-Cu) composition with pressure-induced have been analyzed using density functional theory calculations. The results indicate that the lattice parameters decrease, the mass densities increase with the pressure-increased. The mechanically stability may improve with the pressure increased appropriately for ternary Al-Fe-Ti and quaternary Al-Fe-Ti-Cr. The Young’s modulus has nothing to do with the pressure-induced, but the bulk modulus increases with the pressure increased. The elastic properties were also calculated using Voigt-Reuss-Hill (VRH) approximations. The brittle and ductile properties were studied by Poisson’s ratios and the ratios of shear modulus to bulk modulus. The calculated results of the enthalpy indicate that the binary to hexanary high entropy solid solutions transform the FCC structure to the BCC structure at a certain pressure.

A high-pressure study of HfC and nano-crystalline TiC by X-ray diffraction and density functional theory calculations

2020 ◽  
Vol 34 (34) ◽  
pp. 2050393
Author(s):  
Lun Xiong ◽  
Bin Li ◽  
Bi Liang ◽  
Jinxia Zhu ◽  
Hong Yi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Nano Crystalline

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus [Formula: see text] GPa with [Formula: see text] of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is [Formula: see text] GPa with [Formula: see text].

Structural, Electronic and Elastic Properties of CeTl Intermetallic Compound

2016 ◽  
Vol 28 ◽  
pp. 1-4
Author(s):  
Deepika Shrivastava ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Cscl Type ◽  
Linearized Augmented Plane Wave

The structural, electronic and elastic properties of CeTl with CsCl-type B2 structure have been investigated using full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT) within the generalized gradient approximation (GGA) for exchange and correlation potential. The ground state properties such as lattice constant, bulk modulus and pressure derivative of bulk modulus have been calculated which are in good agreement with available experimental data. The band structure and density of state depict that 4f electrons of Ce element have dominant character in electronic conduction and are responsible for metallic character of CeTl. The charge density plot reveals that the metallic as well as ionic bonding exist between Ce and Tl atoms. The calculated elastic constants indicate that CeTl is mechanically stable in cubic B2 phase and found to be ductile in nature.

The Effect of Nitrogen Doping on the Elastic Properties of Silicene

2015 ◽  
Vol 245 ◽  
pp. 14-18
Author(s):  
Mary A. Chibisova ◽  
Andrey N. Chibisov
Keyword(s):  
Density Functional Theory ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Nitrogen Doping ◽  
Young's Modulus ◽  
Functional Theory ◽  
Nitrogen Doped

This paper deals with the elastic properties of pure and nitrogen-doped silicene using density functional theory. During the compression (tension) from –2 to 2 GPa of pure and nitrogen-doped silicene, the corresponding values for the bulk modulus are obtained. It is found that the doping of the silicene structure with nitrogen has practically no effect on the value of its bulk modulus. However, the Young's modulus is increased of about 1.25 times.

scholarly journals Elastic Properties and Electronic Properties of MxNy (M = Ti, Zr) from First Principles Calculations

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1640 ◽  
Author(s):  
Yangqi Ji ◽  
Xiaoli Yuan
Keyword(s):  
Electronic Properties ◽  
Elastic Properties ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Central Force ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Space Group ◽  
Group I

The elastic properties and electronic properties of MxNy (M = Ti, Zr) TiN, Ti2N, Zr3N4, ZrN with different structures have been investigated using density functional theory. Through the calculation of the elastic constants, it was found that all of these structures meet the mechanical stability except for ZrN with space group P63mc. Their mechanical properties are studied by a comparison of various parameters. The stiffness of TiN is larger than that of ZrN with space group Fm 3 ¯ m. Ti2N’s stiffness with space group I41/amdz is larger than Ti2N with space group P42/mnm. Zr3N4’s stiffness with space group Pnam is largest in three structures of Zr3N4. TiN, Ti2N and ZrN are non-central force, Zr3N4 is central force. TiN and ZrN with space group Fm 3 ¯ m are brittle, and TiN is brittler than ZrN with space group Fm 3 ¯ m. The two kinds of Ti2N are brittle and Ti2N with space group I41/amdz is larger. Three structures of Zr3N4 are tough and Zr3N4 with space group I 4 ¯ 3d is the toughest. Meanwhile, the electronic properties of TiN, Ti2N, Zr3N4 and ZrN were calculated, possible superconducting properties of the studied materials were predicted.

scholarly journals Hybrid Density Functional Study of Au2Cs2I6, Ag2GeBaS4, Ag2ZnSnS4, and AgCuPO4 for the Intermediate Band Solar Cells

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3457 ◽  
Author(s):  
Murugesan Rasukkannu ◽  
Dhayalan Velauthapillai ◽  
Ponniah Vajeeston
Keyword(s):  
Density Functional ◽  
Mechanical Stability ◽  
Density Functional Theory Calculations ◽  
Functional Study ◽  
Photovoltaic Devices ◽  
Hybrid Functional ◽  
Functional Theory ◽  
Intermediate Band ◽  
Intermediate Band Solar Cells ◽  
Hybrid Density Functional

We present a comprehensive investigation of the structural, electronic, mechanical, and optical properties of four promising candidates, namely Au2Cs2I6, Ag2GeBaS4, Ag2ZnSnS4, and AgCuPO4, for application in photovoltaic devices based on intermediate band (IB) cells. We perform accurate density functional theory calculations by employing the hybrid functional of Heyd, Scuseria, and Erhzerhof (HSE06). Calculations reveal that IBs are present in all proposed compounds at unoccupied states in the range of 0.34–2.19 eV from the Fermi level. The structural and mechanical stability of these four materials are also systematically investigated. Additional peaks are present in the optical spectra of these compounds, as characterised by a broadened energy range and high intensity for light absorption. Our findings, as reported in this work, may provide a substantial breakthrough on the understanding of these materials, and thus help the design of more efficient IB solar devices.

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