scholarly journals Structural, electronic and thermoelectric properties of the intermetallic materials based on Mg2X (X= Si, Ge, Sn): DFT calculations

2017 ◽  
Vol 2 (2) ◽  
pp. 25
Author(s):  
Miloud Ibrir

The scope of this work is the investigation of the physical properties of chalcopyrite materials using ab-initio methods in order to simulate a new structure of thin-films photovoltaic cells with high conversion efficiency. In the first framework, we obtained the results of calculations based on Density Functional Theory (DFT) using the full-potential linearized augmented plane wave method (FP-LAPW) as involved in the WIEN2K computational package. For the exchange-correlation potential, the local density approximation (LDA) was used to calculate the lattice parameters, Bulk modulus and its first derivative as well as the densities of states of the intermetallic semiconductors materials based on Mg2X (X=Si, Ge and Sn). The semi-local Becke-Johnson (mBJ) potential and its modified form proposed by Tran and Blaha (TB-mBJ) were also used for studying the electronic and thermoelectric properties; (merit factor, Seebeck coefficient, electronic conductivity). The achieved results were compared to computational works and other data acquired experimentally.

1993 ◽  
Vol 07 (01n03) ◽  
pp. 520-523
Author(s):  
J. I. LEE ◽  
S. K. HWANG ◽  
S. C. HONG ◽  
A. J. FREEMAN

The electronic structure and surface energy of Zr(0001) is determined theoretically using the all-electron full-potential linearized augmented plane wave method based on local-density functional theory. We found the value of surface energy to be 1.6 J/m 2 which is comparable to the value estimated from experiments on liquid zirconium at the melting point. It is, however, much smaller than the surface energies of W(001), V(001) and bcc Co(001). The calculated valence charge density, workfunction, and layer projected density of states for Zr(0001) are also presented.


2019 ◽  
Vol 297 ◽  
pp. 82-94
Author(s):  
Amira El Hassasna ◽  
Abderrachid Bechiri

In this work we investigated the structural, electronic and elastic properties of TlN, TlP, TlAs and TlSb compounds in the zinc-blende phase, the lattice parameter, bulk modulus, band structure, and elastic constants have been calculated by employing the full potential linearized augmented plane wave method based on density functional theory of the exchange-correlation potentials including local density approximation, PBE generalized gradient, and Wu-Cohen generalized gradient are used. Furthermore, the modified Backe-Johnson (mBJ) potential has been utilized for the calculation of the energy gap. The present results are compared with other available theoretical values obtained.


2021 ◽  
Vol 1028 ◽  
pp. 199-203
Author(s):  
Fiqhri Heda Murdaka ◽  
Edi Suprayoga ◽  
Abdul Muizz Pradipto ◽  
Kohji Nakamura ◽  
Agustinus Agung Nugroho

We report the estimation of muon sites inside Mn3Sn using density functional theory based on the full-potential linearized augmented plane wave (FLAPW) calculation. Our calculation shows that the Perdew–Burke–Ernzerhof (PBE) Generalized-Gradient Approximation (GGA) functional is closer to the experimental structure compared to the von Barth-Hedin Local Density Approximation (LDA)-optimized geometry. The PBE GGA is therefore subsequently used in FLAPW post-calculation for the electrostatic potential calculation to find the local minima position as a guiding strategy for estimating the muon site. Our result reveals at least two muon sites of which one is placed at the center between two Mn-Sn triangular layers (A site) and the other at the trigonal prismatic site of Sn atom (B site). The total energy of Mn3Sn system in the presence of muon at A site or B site are compared and we find that A site is a more favorable site for muon to stop.


2002 ◽  
Vol 721 ◽  
Author(s):  
G. Y. Guo

AbstractLatest first-principles density functional theoretical calculations using the generalized gradient approximation and highly accurate all-eleectron full-potential linearized augmented plane wave method, show that bulk hcp Cr would be a paramagnet and that no ferromagnetic state could be stabilized over a wide range of volume [1]. To understand the recent observation of the weakly ferromagnetic state of Cr in hcp Cr/Ru (0001) superlattices [2], the same theoretical calculations have been carried out for the hcp Cr3/Ru7 (0001) and hcp Cr3/fcc Cu6 (111) superlattices. The Cr/Ru superlattice is found to be ferromagnetic with a small magnetic moment of ∼0.31μB/Cr while in contrast, Cr/Cu superlattice is found to be nonmagnetic.


2019 ◽  
Vol 33 (21) ◽  
pp. 1950234
Author(s):  
T. Ghellab ◽  
H. Baaziz ◽  
Z. Charifi ◽  
K. Bouferrache ◽  
Ş Uğur ◽  
...  

Based on the density functional theory (DFT) implemented by the wien2k code which uses the full potential linearized augmented plane wave plus local orbitals (APW + lo) method, we have been able to study different physical properties of X[Formula: see text]PN2 (X = Li, Na) chalcopyrite such as structural, electronic, elastic and thermoelectric properties. According to our calculations, we have found that our structural and electronic parameters, such as the lattice parameter, energy bandgap, the tetragonal ratio, the displacement of the anions, are in very good agreement with the previous experimental and theoretical results. Based on the Voigt–Reuss–Hill approximations, we were able to compute the elastic constants: the compressibility, Young’s and the shear’s moduli, the average velocity of the elastic waves, the Debye temperature and the Poisson’s coefficient of the chalcopyrite LiPN2 and NaPN2. The elastic anisotropy is estimated and further illustrated by the three-dimensional (3D) direction of Young’s and Bulk’s moduli. Finally, using the semi-classical Boltzmann theory implemented in the BolzTraP code, we calculated the transport properties such as the Seebeck coefficient, the thermal electrical conductivity and the figure of merit of these materials.


2016 ◽  
Vol 71 (2) ◽  
pp. 125-134 ◽  
Author(s):  
M’hamed Larbi ◽  
Rabah Riane ◽  
Samir F. Matar ◽  
Ahmed Abdiche ◽  
Mustapha Djermouni ◽  
...  

AbstractOriginal first-principles calculations were performed to study the structural and electronic properties of quaternary BxAlyGa1–x–yN compounds, using the non-relativistic full-potential linearized augmented plane wave method as employed in the Wien2k code. For the exchange-correlation potential, local density approximation and generalized gradient approximation have been used to calculate theoretical lattice parameters, bulk modulus, and their pressure derivatives. Non-linear variation with compositions x and y of the lattice parameter, bulk modulus, and direct and indirect band gaps have been found. The calculated bowing of the fundamental band gaps is in good agreement with the available experimental and theoretical values.


1985 ◽  
Vol 63 ◽  
Author(s):  
Arthur J. Freeman ◽  
C. L. Fu ◽  
T. Oguchi

ABSTRACTAdvances in all-electron local density functional theory approaches to complex materials structure and properties made possible by the implementation of new computational/theoretical algorithms on supercomputers are exemplified in our full potential linearized augmented plane wave (FLAPW) method. In this total energy self-consistent approach, high numerical stability and precision (to 10 in the total energy) have been demonstrated in a study of the relaxation and reconstruction of transition metal surfaces. Here we demonstrate the predictive power of this method for describing the structural, magnetic and electronic properties of several systems (surfaces, overlayers, sandwiches, and superlattices).


2017 ◽  
Vol 27 (1) ◽  
pp. 65
Author(s):  
Hieu T. Nguyen-Truong ◽  
Tan-Tien Pham ◽  
Nam H. Vu ◽  
Dang H. Ngo ◽  
Hung M. Le

We study the energy-loss function for lead in the framework of the time-dependent density functional theory, using the full-potential linearized augmented plane-wave plus local orbitals method. The ab initio calculations are performed in the adiabatic local density approximation. The comparison between the obtained energy-loss function for zero momentum transfer with those from reflection electron energy loss spectroscopy measurements and from first-principles calculations shows good agreement.


2013 ◽  
Vol 209 ◽  
pp. 156-159
Author(s):  
N.L. Heda ◽  
Alpa Dashora ◽  
Jagrati Sahariya ◽  
B.L. Ahuja

We have computed the Mulliken’s population (MP) to deduce charge transfer from WO in semiconducting WO3 using density functional theory (DFT) within pseudopotential scheme. In the DFT scheme, second order generalized gradient approximation for exchange and correlation has been implemented for the first time. The MP data show significant difference in charge transfer between W and six non–equivalent O atoms. In addition, the full potential linearized augmented plane wave method has been applied to compute the partial and total density of states. The MP data have also been explained in terms of partial DOS.


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