A computational estimation on structural, electronic, elastic, optic and dynamic properties of Li2TlA (A=Sb and Bi): First-principles calculations

2022 ◽  
Vol 138 ◽  
pp. 106302
Author(s):  
Emel Kilit Dogan ◽  
Sinem Erden Gulebaglan
Keyword(s):  
First Principles ◽  
Dynamic Properties ◽  
First Principles Calculations ◽  
Computational Estimation

scholarly journals First-principles calculations of structural, electronic, magnetic and elastic properties of Mo 2 FeB 2 under high pressure

2018 ◽  
Vol 5 (7) ◽  
pp. 172247
Author(s):  
Bin Wang ◽  
Benyuan Ma ◽  
Wei Song ◽  
Zhe Fu ◽  
Zhansheng Lu
Keyword(s):  
Heat Capacity ◽  
High Pressure ◽  
Elastic Properties ◽  
First Principles ◽  
Dynamic Properties ◽  
Magnetic Moments ◽  
Debye Model ◽  
Ferromagnetic Phase ◽  
First Principles Calculations ◽  
Anisotropy Index

The structural, electronic, magnetic and elastic properties of Mo 2 FeB 2 under high pressure have been investigated with first-principles calculations. Furthermore, the thermal dynamic properties of Mo 2 FeB 2 were also studied with the quasi-harmonic Debye model. The volume of Mo 2 FeB 2 decreases with the increase in pressure. Using the analysis of the density of the states, atom population and Mulliken overlap population, it is observed that as the pressure increases, the B–B bonds are strengthened and the B–Mo covalency decreases. Moreover, for all pressures, Mo 2 FeB 2 is detected in the anti-ferromagnetic phase and the magnetic moments decrease with the increase in pressure. The calculated bulk modulus, shear modulus, Young's modulus, Poisson's ratio and universal anisotropy index all increase with the increase in pressure. From thermal expansion coefficient analysis, it is found that Mo 2 FeB 2 shows good volume invariance under high pressure and temperature. The examination of the dependence of heat capacity on the temperature and pressure shows that heat capacity is more sensitive to temperature than to pressure.

scholarly journals First-Principles Study of the Structural Stability and Dynamic Properties of Li2MSiO4 (M = Mn, Co, Ni) Polymorphs

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Ponniah Vajeeston ◽  
Federico Bianchini ◽  
Helmer Fjellvåg
Keyword(s):  
Structural Stability ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Li Ion

In recent years, the scientific community has shown an increasing interest in regards to the investigation of novel materials for the intercalation of lithium atoms, suitable for application as cathodes in the new generations of Li-ion batteries. Within this framework, we have computed the relative structural stability, the electronic structure, the elastic and dynamic properties of Li2MSiO4 compounds (M = Mn, Co, Ni) by means of first-principles calculations based on density functional theory. The so-obtained structural parameters of the examined phases are in agreement with previous reports. The energy differences between different polymorphs are found to be small, and most of these structures are dynamically stable. The band structures and density of states are computed to analyse the electronic properties and characterise the chemical bonding. The single crystal elastic constants are calculated for all the examined modifications, proving their mechanical stability. These Li2MSiO4 materials are found to present a ductile behaviour upon deformation. The diffusion coefficients of Li ions, calculated at room temperature for all the examined modifications, reveal a poor conductivity for this class of materials.

First-Principles Investigations of Electronic, Dynamic and Thermodynamic Properties of α-MnO2

2014 ◽  
Vol 936 ◽  
pp. 591-595 ◽  
Author(s):  
Ai Min Hao ◽  
Na Qi Wang
Keyword(s):  
Thermodynamic Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Dynamic Properties ◽  
Thermodynamic Quantities ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Direct Band Gap ◽  
Direct Band

We investigate the electronic, dynamic and thermodynamic properties of α-MnO2 using first-principles calculations based on density functional theory (DFT) with the GGA+U method. The results of electronic structures show that α-MnO2is a semiconductor with a direct band gap of 1.4 eV at Γ point. The results of dynamic properties indicate that the structure of α-MnO2 is dynamically unstable at ground-state. Several important thermodynamic quantities, such as entropy, enthalpy and Gibbs free energy, et al each as a function of temperature were presented.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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