First-principles Calculations of Energetic Properties of Vacancies, Mn-atomic Defects in CdTe

2006 ◽  
Vol 959 ◽  
Author(s):  
Ghouti Merad ◽  
Benali Rerbal ◽  
Hafid Aourag ◽  
Joël Cibert

ABSTRACTAn atomistic modelling based on density functional theory within the framework of the local density approximation is used to show the trends in the energetic properties of single and double defects in CdTe semiconductor, without phase transformation. A systematic study of vacancies, Mn substituting Cd atoms in a supercell structure consisting of 16-atoms is presented. The changes of structural properties and lattice parameters due to the addition of Mn-atomic type defects in CdTe matrix are compared, and the number of vacancies is also determined from the total energy calculations.

2016 ◽  
Vol 30 (21) ◽  
pp. 1650147 ◽  
Author(s):  
S. Ferahtia ◽  
S. Saib ◽  
N. Bouarissa

The present study deals with first-principles calculations of the thermal properties of ZnTe in the two phases namely, zinc-blende and wurtzite. The calculations are mainly performed using the density functional theory with the local density approximation and response-function calculations. The full phonon dispersions throughout the Brillouin zone are presented. The temperature dependence of the lattice parameters, bulk modulus, entropy and heat capacity are examined and discussed. Our findings agree reasonably well with those available in the literature.


2017 ◽  
Vol 31 (23) ◽  
pp. 1750175 ◽  
Author(s):  
Margi Jani ◽  
Abhijit Ray

We investigated the electronic and optical properties of ZnO under the circumstances of isovalent anionic doping by sulfur. A pseudopotential implementation of density functional theory is applied within the local density approximation to examine the modification of band structure in wurtzite ZnO by sulfur substitution. Although Fermi level position does not change, a strong localization of Zn-[Formula: see text] orbital is found by S-doping. Optical properties and constants are found to strongly depend on the sulfur content at low photon energies.


2002 ◽  
Vol 718 ◽  
Author(s):  
J. B. Neaton ◽  
C.-L. Hsueh ◽  
K. M. Rabe

AbstractThe structure, polarization, and zone-center phonons of bulk tetragonal BaTiO3 under compressive epitaxial stress are calculated using density functional theory within the local density approximation. The polarization, computed using the Berry-phase formalism, increases with increasing tetragonality and is found to be enhanced by nearly 70% for the largest compressive misfit strain considered (-2.28%). The results are expected to be useful for the analysis of coherent epitaxial BaTiO3 thin films and heterostructures grown on perovskite substrates having a smaller lattice constant, such as SrTiO3.


2007 ◽  
Vol 131-133 ◽  
pp. 241-246 ◽  
Author(s):  
P. Śpiewak ◽  
Krzysztof Jan Kurzydlowski ◽  
Koji Sueoka ◽  
Igor Romandic ◽  
Jan Vanhellemont

Density functional theory (DFT) with local density approximation has been used to calculate the formation energy (EF) of the neutral vacancy in germanium single crystal. It was shown that careful checking of convergence with respect to the number of k-points is necessary when calculating the formation energy of the intrinsic point defects in Ge. The formation energy of the single neutral vacancy was estimated at 2.35 eV which is in excellent agreement with published experimental data.


2011 ◽  
Vol 239-242 ◽  
pp. 1231-1234
Author(s):  
Qi Jun Liu ◽  
Zheng Tang Liu ◽  
Li Ping Feng ◽  
Hao Tian

The electronic properties of N-doped orthorhombic SrHfO3 have been calculated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory with the local density approximation. From the calculated band structure and density of states, the bandgap reduction is observed due to the presence of the N-2p states in the top of valence bands, which leads to red-shift. Moreover, in order to clarify the charge transfer and bonding properties of N-doped orthorhombic SrHfO3, we have calculated and analysed the charge density.


2021 ◽  
Author(s):  
H. R. Mahida ◽  
Deobrat Singh ◽  
Yogesh Sonvane ◽  
Sanjeev K. Gupta ◽  
P. B. Thakor ◽  
...  

In the present study, we have investigated the structural, electronic, and charge transport properties of pristine, hydrogenated, and oxidized Si2BN monolayers via first-principles calculations based on density functional theory (DFT).


2017 ◽  
Vol 19 (5) ◽  
pp. 3679-3687 ◽  
Author(s):  
Tao Yang ◽  
Masahiro Ehara

Using density functional theory calculations, we discussed the geometric and electronic structures and nucleation of small Co clusters on γ-Al2O3(100) and γ-Al2O3(110) surfaces.


2015 ◽  
Vol 17 (45) ◽  
pp. 30598-30605 ◽  
Author(s):  
Ming-Kai Hsiao ◽  
Chia-Hao Su ◽  
Ching-Yang Liu ◽  
Hui-Lung Chen

We employed monolayer tungsten metal to modify the Fe(111) surface, denoted as W@Fe(111), and calculated the adsorption and dehydrogenation behaviors of NH3 on W@Fe(111) surface via first-principles calculations based on density functional theory (DFT).


2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.


2009 ◽  
Vol 1200 ◽  
Author(s):  
Markus E. Gruner

AbstractThis contribution reports static ionic displacements in ferromagnetic disordered Fe70Pd30 alloys obtained by relaxation of the ionic positions of a 108-atom supercell within the framework of density functional theory. Comparison with a simple statistical model based on Lennard-Jones pair interactions reveals that these displacements are significantly larger than can be explained by the different sizes of the elemental constituents. The discrepancies are presumably related to collective displacements of the Fe atoms. Corresponding distortions are experimentally observed for ordered Fe3Pt and predicted by first-principles calculations for all ordered Fe-rich L12 alloys with Ni group elements and originate from details of the electronic structure at the Fermi level.


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