scholarly journals Electronic Structure of Intermetallic Antiferromagnet GdNiGe

Symmetry ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 737
Author(s):  
Evgenii D. Baglasov ◽  
Alexey V. Lukoyanov
Keyword(s):  
Experimental Data ◽  
Electronic Structure ◽  
Generalized Gradient ◽  
Antiferromagnetic Ordering ◽  
Equilibrium Volume ◽  
Spin Polarized ◽  
Ternary Intermetallic Compound ◽  
Experimental Crystal ◽  
Experimental Crystal Structure ◽  
Calculated Equilibrium

The electronic structure of the GdNiGe ternary intermetallic compound was investigated in this work. We carried out the spin-polarized DFT+U calculations of its band structure within generalized gradient approximation accounting for strong electronic correlations in the 4f-shell of gadolinium ions. The antiferromagnetic ordering was reproduced in the calculations, in agreement with experimental data. The calculated equilibrium volume is within 2% accuracy to the experimental crystal structure data, which demonstrates the reliability of the method chosen. The 4f-shell of Gd was demonstrated to substantially contribute to the spectral and magnetic properties of the GdNiGe compounds, whereas other ions were found nonmagnetic, in agreement with experimental data.

FIRST PRINCIPLES STUDY OF THE ELECTRONIC STRUCTURE AND FERROMAGNETISM OF THE V-DOPED BN(5, 5) NANOTUBE

2008 ◽  
Vol 22 (18) ◽  
pp. 1749-1756 ◽  
Author(s):  
K. H. HE ◽  
G. ZHENG ◽  
G. CHEN ◽  
M. WAN ◽  
G. F. JI
Keyword(s):  
Electronic Structure ◽  
Magnetic Moment ◽  
First Principles ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Ferromagnetic Properties ◽  
Generalized Gradient Approximation ◽  
First Principles Study ◽  
Spin Polarized

The structural, electronic and ferromagnetic properties of the V-doped BN(5, 5) are investigated by using first-principles spin-polarized calculations within generalized gradient approximation. The optimized structure shows that the V atom moves outwards and the hexagonal rings with the V atom experience significant distortion. The electronic structure indicates that the V-doped BN(5, 5) nanotube is half-metallic. The majority ferromagnetic moment comes from the V atom and slight magnetic moment is provided by the B atoms which are near to the V atom, while a little negative magnetic moment is contributed by the N atoms.

Interstitial vs. Substitutional Metal Insertion in V2O5 as Post-Lithium Ion Battery Cathode: A Comparative GGA/GGA+U Study with Localized Bases

2020 ◽  
Author(s):  
Daniel Koch ◽  
Sergei Manzhos
Keyword(s):  
Electronic Structure ◽  
Plane Wave ◽  
Transition Metal Oxides ◽  
Reasonable Agreement ◽  
Correction Term ◽  
Lithium Ion ◽  
Generalized Gradient ◽  
Main Group Metals ◽  
Generalized Gradient Approximation ◽  
Metal Insertion

<p></p><p>The generalized gradient approximation (GGA) often fails to correctly describe the electronic structure and thermochemistry of transition metal oxides and is commonly improved using an inexpensive correction term with a scaling parameter <i>U</i>. We tune <i>U</i> to reproduce experimental vanadium oxide redox energetics with a localized basis and a GGA functional. We find the value for <i>U</i> to be significantly lower than what is generally reported with plane-wave bases, with the uncorrected GGA results being in reasonable agreement with experiments. We use this computational setup to calculate interstitial and substitutional <a>insertion energies of main group metals in vanadium pentoxide</a> and find <a>interstitial doping to be thermodynamically favored</a>.</p><p></p>

Effect of Chromium and Vanadium on Nanolayered Ternary Carbides: AB Initio Study

2009 ◽  
Vol 609 ◽  
pp. 239-242
Author(s):  
A.E. Merad ◽  
M.B. Kanoun
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Ab Initio ◽  
Structural Parameters ◽  
Ab Initio Study ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Full Relaxation ◽  
Relaxation Procedure ◽  
Ternary Carbides

The Cr2AlC and V2AlC nanolayered ternary carbides are studied by performing APW-lo ab initio total energy calculations within the recent Wu-Cohen generalized gradient approximation GGA. Using full relaxation procedure of the volume and the atomic positions we obtained the structural parameters and electronic structure of the optimization hexagonal. Results were compared with the experimental ones. Interesting features are deduced. In fact, we have shown why these materials are conductors.

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

Electronic Structure Of (AgSb)xPbn-2xTen

2003 ◽  
Vol 793 ◽  
Author(s):  
Daniel I Bilc ◽  
S.D. Mahanti ◽  
M.G. Kanatzidis
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Two Component System ◽  
Functional Theory ◽  
Covalent Interaction ◽  
Salt Structure ◽  
Linearized Augmented Plane Wave

ABSTRACTComplex quaternary chalcogenides (AgSb)xPbn-2xTen (0<x<n/2) are thought to be narrow band-gap semiconductors which are very good candidates for room and high temperature thermoelectric applications. These systems form in the rock-salt structure similar to the well known two component system PbTe (x=0). In these systems Ag and Sb occupy Pb sites randomly although there is some evidence of short-range order. To gain insights into the electronic structure of these compounds, we have performed electronic structure calculations in AgSbTe2 (x=n/2). These calculations were carried out within ab initio density functional theory (DFT) using full potential linearized augmented plane wave (LAPW) method. The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. Spinorbit interaction (SOI) was incorporated using a second variational procedure. Since it is difficult to treat disorder in ab initio calculations, we have used several ordered structures for AgSbTe2. All these structures show semimetallic behavior with a pseudogap near the Fermi energy. Te and Sb p orbitals, which are close in energy, hybridize rather strongly indicating a covalent interaction between Te and Sb atoms.

First principles study of the structural, electronic and optical properties of crystalline o-phenanthroline

2016 ◽  
Vol 30 (14) ◽  
pp. 1650077 ◽  
Author(s):  
Hajar Nejatipour ◽  
Mehrdad Dadsetani
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Binding Energies ◽  
Many Body ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Independent Particle ◽  
Excitonic Effects ◽  
Comprehensive Study

In a comprehensive study, structural properties, electronic structure and optical response of crystalline o-phenanthroline were investigated. Our results show that in generalized gradient approximation (GGA) approximation, o-phenanthroline is a direct bandgap semiconductor of 2.60 eV. In the framework of many-body approach, by solving the Bethe–Salpeter equation (BSE), dielectric properties of crystalline o-phenanthroline were studied and compared with phenanthrene. Highly anisotropic components of the imaginary part of the macroscopic dielectric function in o-phenanthroline show four main excitonic features in the bandgap region. In comparison to phenanthrene, these excitons occur at lower energies. Due to smaller bond lengths originated from the polarity nature of bonds in presence of nitrogen atoms, denser packing, and therefore, a weaker screening effect, exciton binding energies in o-phenanthroline were found to be larger than those in phenanthrene. Our results showed that in comparison to the independent-particle picture, excitonic effects highly redistribute the oscillator strength.

The physical properties of ThCr2Si2-type superconductors MPd2P2 (M = Y, La): A theoretical investigation

2018 ◽  
Vol 32 (28) ◽  
pp. 1850312
Author(s):  
Md. Lokman Ali ◽  
Md. Tosaddek Hossen ◽  
Shahin Alam ◽  
Md. Sadek Hossain ◽  
Jakiul Islam ◽  
...  
Keyword(s):  
Experimental Data ◽  
Elastic Constants ◽  
Structural Data ◽  
Computer Code ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Anisotropic Factor ◽  
Optical Functions ◽  
Debye Temperatures ◽  
Ductile Behavior

The structural stability, elastic, mechanical, optical characteristics and Debye temperature of single crystalline superconductors MPd2P2 (M = Y, La) were investigated by using the ab initio technique. We have carried out the plane wave pseudopotential within the generalized gradient approximation (GGA) implemented in the CASTEP computer code. Our investigated results of structural data are in well consistent with the previous experimental data. The bulk modulus B, shear modulus G, Young’s modulus E, Poisson’s ratio v, hardness H, and anisotropic factor A of MPd2P2 (M = Y, La) compounds were evaluated from the calculated elastic constants. The analysis of ratio B/G shows that the MPd2P2 superconductors are in ductile behavior. The Debye temperatures are also investigated from the elastic constants. Finally, the optical functions including reflectivity, absorption coefficient, loss function, conductivity, refractive index, dielectric function are calculated and analyzed.

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