Structural and Electronic Properties of Narrow Gap Zincblende and Chalcopyrite Compounds

1990 ◽  
Vol 193 ◽  
Author(s):  
T.M. de Pascale ◽  
F. Meloni ◽  
M. Serra ◽  
S. Massidda ◽  
A. Continenza ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Full Potential ◽  
Narrow Gap ◽  
Augmented Plane Wave ◽  
Bulk Semiconductors ◽  
Structural And Electronic Properties ◽  
Indium Compounds ◽  
Linearized Augmented Plane Wave ◽  
Ternary Semiconductors

ABSTRACTIndium compounds and corresponding epitaxially grown superlattices have provided good single crystals suitable for accurate experimental measurements and have added new interest to the study of the constituent bulk semiconductors and the II-IV-V2 chalcopyrite crystal phases. This paper reports results of structural and electronic properties of narrow gap binary and ternary semiconductors determined selfconsistently from first principles using both the full potential linearized augmented plane wave (FLAPW) and norm-conserving pseudopotentials (PP) total-energy methods.

CORRELATION BETWEEN LOCAL OXYGEN DISORDER AND ELECTRONIC PROPERTIES IN SUPERCONDUCTING RESR2CU3O6+X(RE = Y, YB)

2003 ◽  
Vol 17 (04n06) ◽  
pp. 873-878 ◽  
Author(s):  
A. PRODI ◽  
A. GAUZZI ◽  
E. GILIOLI ◽  
F. LICCI ◽  
M. MAREZIO ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Local Density ◽  
Full Potential ◽  
Orthorhombic Distortion ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Structural And Electronic Properties ◽  
Large Elastic Strain ◽  
Linearized Augmented Plane Wave ◽  
Local Oxygen

This work aims at understanding the large reduction of superconducting critical temperature Tc observed in YSr 2 Cu 3 0 6+x as compared to its YBa 2 Cu 3 O 6+x counterpart (ΔTc = -30 K ). We report on a combined study of structural and electronic properties of RESr 2 Cu 3 O 6+x(RE = Y, Yb) polycrystalline samples. Neutron diffraction data and Cu NQR spectra show that, contrary to REBa 2 Cu 3 O 6+x RESr 2 Cu 3 O 6+x is locally tetragonal and no CuO chains are formed. This arises from the random occupancy of oxygen along the a- or b- direction in the basal planes. Ab-initio calculations of the electronic structure using the full-potential linearized-augmented-plane-wave method (FLAPW) in the local density approximation (LDA) suggest that the CuO chains are not formed because of the large elastic strain associated with the orthorhombic distortion produced by the chain formation. In addition, by using a [Formula: see text] supercell simulating the absence of chains, we find that oxygen disorder greatly alters the band structure near the Fermi level. Our analysis indicates that this alteration leads to a reduction of hole transfer from the CuO chains to the CuO 2 planes, which accounts for the reduction of Tc experimentally observed.

scholarly journals Study of Structural and Electronic Properties of Fluoride Perovskite KCaF3 using FP-LAPW Method

2017 ◽  
pp. 100-103
Author(s):  
K. Neupane ◽  
R. K. Thapa
Keyword(s):  
Electronic Properties ◽  
First Principles Calculation ◽  
Exchange Potential ◽  
Full Potential ◽  
Pressure Derivative ◽  
Augmented Plane Wave ◽  
Exchange Correlation ◽  
Equilibrium Lattice Constant ◽  
Structural And Electronic Properties ◽  
Linearized Augmented Plane Wave

To study the structural and electronic properties of cubical perovskite KCaF3, the first principles calculation within the full potential linearized augmented plane wave (FP-LAPW) method is applied. The exchange correlation effects are included through the GGA exchange potential. The calculated structural properties such as equilibrium lattice constant, the bulk modulus and its pressure derivative are in agreement with the published results of other authors. From our study we have found that the band gap of KCaF3 is 6.4 eV which is the indication of insulating behavior.The Himalayan Physics Vol. 6 & 7, April 2017 (100-103)

Structural And Electronic Properties of GaN/AL Interfaces

1997 ◽  
Vol 482 ◽  
Author(s):  
S. Picozzi ◽  
A. Continenza ◽  
S. Massidda ◽  
A. J. Freeman
Keyword(s):  
Electronic Properties ◽  
Ohmic Contacts ◽  
Local Density ◽  
Full Potential ◽  
Junction Region ◽  
Augmented Plane Wave ◽  
Structural And Electronic Properties ◽  
Transitivity Rule ◽  
Gap States ◽  
Linearized Augmented Plane Wave

AbstractThe structural and electronic properties of the GaN/Al interface are determined from first principles local density full potential linearized augmented plane wave (FLAPW) calculations. The charge distribution of the gap states as a function of the distance from the interface shows that the gap states induced into the semiconductor by the presence of Al are strongly localized in the junction region. Furthermore, we find that Al does not provide good ohmic contacts on the clean nitrides considered, in contrast with experimental results on chemically treated GaN, but in agreement with recent measurements on the clean surface[1]. We also study some auxiliary systems (all grown on a GaN substrate), i.e. the Al/AlN interface, the GaN/AlN heterojunction and the GaN/Al with an AlN intralayer (GaN-AlN/Al). The transitivity rule for the GaN/Al, AlN/Al and GaN/AlN interfaces is fairly well satisfied and small differences must be ascribed to differences in the interface morphology. Finally, we find that the AIN intralayer does not significantly affect the p-type Schottky barrier height of the GaN/Al interface.

FIRST-PRINCIPLE THEORETICAL STUDY ON THE CALCIUM FERRITE-TYPE LiMn2O4

2010 ◽  
Vol 03 (02) ◽  
pp. 93-96 ◽  
Author(s):  
MEILING LI ◽  
YUE ZHANG ◽  
LIN LI
Keyword(s):  
Magnetic Moments ◽  
Mixed Valence ◽  
Calcium Ferrite ◽  
Full Potential ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Augmented Plane Wave Method ◽  
Structural And Electronic Properties ◽  
Mixed Valence Compound ◽  
Linearized Augmented Plane Wave

The structural and electronic properties of the calcium ferrite-type LiMn 2 O 4 were studied using the full-potential linearized augmented plane wave method. The results showed that LiMn 2 O 4 was an antiferromagnetic semiconductor from GGA+U calculations, similar to the experimental report of Li 0.92 Mn 2 O 4. The spin magnetic moments and density of states of Mn atoms showed that LiMn 2 O 4 was a mixed-valence compound with Mn 3+ and Mn 4+ cations randomly distributed amongst the octahedral sites.

Ab initio studies of the structural, electronic, and optical properties of quaternary BxAlyGa1–x–yN compounds

2016 ◽  
Vol 71 (2) ◽  
pp. 125-134 ◽  
Author(s):  
M’hamed Larbi ◽  
Rabah Riane ◽  
Samir F. Matar ◽  
Ahmed Abdiche ◽  
Mustapha Djermouni ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Local Density ◽  
Lattice Parameter ◽  
Band Gaps ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Structural And Electronic Properties ◽  
Linearized Augmented Plane Wave

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.

First-principles calculations of electronic and magnetic properties of XMn2Y2 (X = Ca, Sr; Y = Sb, Bi) compounds

2019 ◽  
Vol 33 (18) ◽  
pp. 1950199
Author(s):  
Zeshan Zada ◽  
A. Laref ◽  
G. Murtaza ◽  
Aurang Zeb ◽  
A. Yar
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Full Potential ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Spin Configuration ◽  
Augmented Plane Wave ◽  
Electronic And Magnetic Properties ◽  
Magnetic Stability ◽  
Linearized Augmented Plane Wave

We have examined the magnetic stability; antiferromagnetic (AFM) ordering; electronic and magnetic properties of composition XMn2Y2 (X = Ca, Sr; Y = Sb, Bi) using framework of full-potential linearized augmented plane wave (FP-LAPW) method within generalized gradient (PBE-GGA) approximations in AFM phase. We have specified that AFM state is most suitable for these compounds as compared to other configurations at their relaxed lattice parameters. An AFM spin configuration of Mn atoms is shown to be impressive state for these compounds. Based on its electronic properties, these compounds have a metallic nature in Paramagnetic (PM) but in AFM phase it shows different nature from PM phase. From a suitable phase, it has been cleared that both Mn atoms well-adjusted antiferromagnetically.

Pressure Effect on the Electronic Properties of Cerium Monochalcogenides CeX (X=S, Se, Te) Using Modified Becke-Johnson Exchange Potential and LDA+U

2014 ◽  
Vol 925 ◽  
pp. 390-395
Author(s):  
Noureddine Amrane ◽  
Maamar Benkraouda
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Exchange Potential ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
The Density Functional Theory ◽  
Linearized Augmented Plane Wave

We present a systematic and comparative study of the electronic properties of CeX monochalcogenides, The density of state (DOS) and electronic band structure of CeX (X=S, Se, Te) have been calculated using the full-potential linearized augmented plane-wave (FP-LAPW) + local orbital (lo) method based on the density functional theory (DFT), which is implemented in WIEN2k code. The trends in the high pressure behavior of these systems are discussed. Four approximations for the exchange-correlation functional have been used, the GGA's of Perdew-Burke-Ernzherhof. (PBE08) , Engel-Vosko (EV93), a modified version of the exchange potential proposed by Becke and Johnson (MBJ), and LDA+U is used to calculate the band gaps at different pressures. All methods allow for a description of the Ce f electrons as either localized or delocalized, it is found that the underestimations of the bandgap by means of LDA-GGA and Engel-Vosko are considerably improved by using the modified Becke-Johnson (MBJ) potential for all compounds in the series, On the other hand, LDA+U, method gives good results for the lighter chalcogenides, but it fails to give good results for the heavier cerium monochalcogenides.

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