Physical properties of ternary silicide superconductors Li2XSi3 (X = Rh, Os): An ab initio study

2017 ◽  
Vol 31 (20) ◽  
pp. 1750135 ◽  
Author(s):  
M. A. Alam ◽  
M. A. K. Zilani ◽  
F. Parvin ◽  
M. A. Hadi
Keyword(s):  
Physical Properties ◽  
Ab Initio ◽  
Ab Initio Method ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Generalized Gradient Approximation ◽  
Bonding Properties ◽  
First Time ◽  
Electronic Band Structures ◽  
Ternary Silicide

An ab initio method, based on the plane wave pseudopotential and the generalized gradient approximation (GGA), is performed to investigate the physical properties such as structural, elastic, electronic and bonding properties of newly synthesized Li2RhSi3 and predicted Li2OsSi3 ternary silicide superconductors for the first time. Both of these compounds are mechanically stable and are brittle in nature. They also have good machinability. Electronic band structures reveal that these compounds have metallic characteristics. They possess complex bonding nature (metallic, covalent and ionic). According to theoretical Vickers hardness, Li2RhSi3 is softer than Li2OsSi3.

scholarly journals An ab-initio Investigation: The physical properties of ScIr-=SUB=-2-=/SUB=- Superconductor -=SUP=-*-=/SUP=-

2019 ◽  
Vol 61 (4) ◽  
pp. 659
Author(s):  
Uttam Kumar Chowdhury ◽  
Tapas Chandra Saha
Keyword(s):  
Physical Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Ultraviolet Region ◽  
Electronic Band ◽  
Cauchy Pressure ◽  
Pseudopotential Approach ◽  
First Time

AbstractUsing ab initio technique the physical properties of ScIr_2 superconductor have been investigated with T _c 1.03 K with a MgCu_2-type structure. We have carried out the plane-wave pseudopotential approach within the framework of the first-principles density functional theory (DFT) implemented within the CASTEP code. The calculated structural parameters confirm a good agreement with the experimental and other theoretical results. Using the Voigt-Reuss-Hill (VRH) averaging scheme the most important elastic properties including the bulk modulus B, shear modulus G , Young’s modulus E and Poisson’s ratio ν of ScIr_2 are determined. At ambient condition, the values of Cauchy pressure and Pugh’s ratio exhibit ductile nature of ScIr_2. The electronic and optical properties of ScIr_2 were investigated for the first time. The electronic band structure reveals metallic conductivity and the major contribution comes from Ir-5 d states. In the ultraviolet region the reflectivity is high up to 50 eV as evident from the reflectivity spectrum.

Electronic band structures of NdFe3(BO3)4 and NdGa3(BO3)4 crystals: ab initio calculations

2021 ◽  
Vol 575 (1) ◽  
pp. 11-17
Author(s):  
S. Krylova ◽  
I. Gudim ◽  
A. Aleksandrovsky ◽  
A. Vtyurin ◽  
A. Krylov
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Band Structures ◽  
Electronic Band ◽  
Electronic Band Structures

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.

scholarly journals Ab-initio study of the orthorhombic ndmno3 perovskite

2014 ◽  
Vol 70 (a1) ◽  
pp. C1806-C1806
Author(s):  
Samir Bentata ◽  
Bouabdellah Bouadjemi ◽  
Tayeb Lantri ◽  
Wissem Benstaali
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Total Density ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Ferromagnetic Ground State ◽  
Total Density Of States

We investigate the structural, electronic and magnetic properties of the orthorhombic Perovskite oxyde NdMnO3 through density-functional-theory (DFT) calculations using both generalized gradient approximation GGA+U, where U is on-site Coulomb interaction correction. The electronic band structure, the partial and total density of states (DOS) and the magnetic moment are determined. The results show a half-metallic ferromagnetic ground state for the orthorhombic NdMnO3.

PSEUDOPOTENTIAL INVESTIGATION OF ELECTRONIC PROPERTIES OF C54- AND C49-TiSi2

2006 ◽  
Vol 20 (07) ◽  
pp. 343-351 ◽  
Author(s):  
TAO WANG ◽  
JI-AN CHEN ◽  
XING LING ◽  
YONG-BING DAI ◽  
QING-YUAN DAI
Keyword(s):  
Solid State ◽  
Plane Wave ◽  
Ab Initio ◽  
Electronic Properties ◽  
Solid State Reaction ◽  
Growth Stage ◽  
Pseudopotential Method ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation

The letter casts some light on the structural, elastic and electronic properties of C49- and C54-TiSi 2, using an ab initio plane-wave ultrasoft pseudopotential method based on generalized gradient approximation (GGA). An intrinsic advantage in the growth stage for C49 phase might explain its kinetically favored phenomena in a solid-state reaction.

Comparison of the electronic band structures of LiCaAlF6and LiSrAlF6ultraviolet laser host media from ab initio calculations

2015 ◽  
Vol 54 (12) ◽  
pp. 122602 ◽  
Author(s):  
Mui Viet Luong ◽  
Marilou Cadatal-Raduban ◽  
Melvin John F. Empizo ◽  
Ren Arita ◽  
Yuki Minami ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Band Structures ◽  
Electronic Band ◽  
Electronic Band Structures

STRUCTURAL, ELECTRONIC, MAGNETIC AND OPTICAL PROPERTIES OF FERROMAGNETIC Pb1-xEuxSe AND Pb1-xEuxTe ALLOYS (x = 0, 0.25, 0.50, 0.75 AND 1)

2013 ◽  
Vol 27 (19) ◽  
pp. 1350100 ◽  
Author(s):  
S. M. ALAY-E-ABBAS ◽  
S. YOUNAS ◽  
S. HANIF ◽  
M. SHARIF ◽  
IQBAL HUSSAIN ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Full Potential ◽  
Nonlinear Behaviour ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Plane Wave Method ◽  
Energy Dependent ◽  
Electronic Band Structures

First-principles total energy calculations have been performed using full potential linear-augmented-plane-wave method within the framework of density functional theory to study the structural, electronic, magnetic and optical properties of the Pb 1-x Eu x Se and Pb 1-x Eu x Te (0 ≤ x ≤1) alloys in the ferromagnetic (FM) ordering. The calculations have been extended to treat the strongly localized f electrons of Eu atom by the self-interaction correction (SIC) approach. For structural optimization, the Wu and Cohen generalized gradient approximation (GGA) functional has been used, whereas for calculating electronic properties, the GGA parameterization scheme formulated by Engel and Vosko (EV) has also been utilized. It has been observed that the use of experimental value of Coulomb parameter (Uf- expt. ) within the SIC does not yield an accurate EuSe and EuTe energy band structure. The improvement in the electronic band structures of nonmagnetic PbSe / PbTe and ferromagnetic EuSe / EuTe have been achieved by considering the effects of spin–orbit coupling for Pb atoms, by a suitable choice of U and by treating the U values for Eu atom's f and d electrons as parameters. The electronic and optical properties of FM Pb 1-x Eu x Se in agreement with experiments can be achieved by combining EV GGA with a Hubbard U < Uf- expt. , however, a stronger and stable AFM coupling in EuTe leaves the above scheme unable to provide good electronic structure of FM Pb 1-x Eu x Te . In case of Pb 1-x Eu x Se the nonlinear behaviour of electronic structure is reflected in the optical properties of Eu -doped PbSe that have been studied in terms of incident photons' energy dependent complex dielectric function.

scholarly journals Ab initio Study of the Structure, Elastic, and Electronic Properties of Ti3(Al1-nSin)C2 Layered Ternary Compounds

2020 ◽  
Author(s):  
S. Ahams ◽  
A. Shaari ◽  
Rashid Ahmed ◽  
N. Abdul Pattah ◽  
M. Idris ◽  
...  
Keyword(s):  
Ab Initio ◽  
Density Of States ◽  
Mechanical Stability ◽  
Electrical Contact ◽  
Ceramic Materials ◽  
Systematic Investigation ◽  
Max Phase ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Pseudopotential Approach

Abstract The MAX phase materials such as layered ternary carbides that simultaneously exhibit characteristics of metallic and ceramic materials have received substantial interest in recent years. Here, we present a systematic investigation of the electronic, structural stabilities, and elastic properties of Ti3(Al1-nSin)C2 (n = 0,1) MAX phase materials using the ab initio method via a plane-wave pseudopotential approach within generalized-gradient-approximations. The computed electronic band structures and projected density of states show that both Ti3SiC2 and Ti3AlC2 are metallic materials with a high density of states at the Fermi level emanating mainly from Ti-3d. Using the calculated elastic constants, the mechanical stability of the compounds was confirmed following the Born stability criteria for hexagonal structures. The Cauchy pressure and the Pugh’s ratio values establish the brittle nature of the Ti3SiC2 and Ti3AlC2 MAX phase materials. Due to their intriguing physical properties, these materials are expected to be suitable for applications such as thermal shock refractories and electrical contact coatings.

Thermomechanical, electronic and thermodynamic properties of ZnS cubic polymorphs: an ab initio investigation on the zinc-blende–rock-salt phase transition

2019 ◽  
Vol 75 (6) ◽  
pp. 1042-1059 ◽  
Author(s):  
Gianfranco Ulian ◽  
Giovanni Valdrè
Keyword(s):  
Phase Transition ◽  
Thermodynamic Properties ◽  
Ab Initio ◽  
Zinc Sulfide ◽  
Rock Salt ◽  
Electronic Band ◽  
Zinc Blende ◽  
Wide Range ◽  
Static Conditions ◽  
First Time

In the present work, an extensive and detailed theoretical investigation is reported on the thermomechanical, electronic and thermodynamic properties of zinc-blende (sphalerite, zb-ZnS) and rock-salt zinc sulfide (rs-ZnS) over a wide range of pressure, by means of ab initio Density Functional Theory, Gaussian type orbitals and the well known B3LYP functional. For the first time, vibrational frequencies, phonon dispersion relations, elasto-piezo-dielectric tensor, thermodynamic and thermomechanical properties of rs-ZnS were calculated with a consistent approach that allows a direct comparison with the low-pressure polymorph. Special attention was paid to the evaluation of the thermodynamic pressure–temperature stability of the mineral phases between 0–25 GPa and 0–800 K. The static (T = 0 K) bulk moduli of sphalerite and rock-salt ZnS were 72.63 (3) GPa and 84.39 (5) GPa, respectively. The phase transition in static conditions calculated from the equation of state was about 15.5 GPa, whereas the elastic constants data resulted in P trans = 14.6 GPa. At room temperature (300 K), the zb-rs transition occurs at 14.70 GPa and a negative Clapeyron slope (dP)/(dT) = 0.0023 was observed up to 800 K. The electronic band structure showed a direct band gap for zb-ZnS (E g = 4.830 eV at equilibrium geometry), which became an indirect one by increasing pressure above 11 GPa. The results were found to be in good agreement with the available experimental and theoretical data, further extending the knowledge of important properties of zinc sulfide, in particular the thermomechanical ones of the rock-salt polymorph here extensively explored for the first time.

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