Electronic properties of austenite and martensite Fe-9%Mn alloys

Open Physics ◽  
2008 ◽  
Vol 6 (4) ◽  
Author(s):  
Ercan Uçgun ◽  
Hamza Ocak
Keyword(s):  
Total Energy ◽  
Electronic Properties ◽  
Lattice Relaxation ◽  
The Self ◽  
Full Potential ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
Generalized Gradient Approximation ◽  
Self Consistent

AbstractWe calculate the electronic properties of austenite and martensite Fe-9%Mn alloys using the self consistent full-potential linearized-plane-wave method under the generalized gradient approximation full lattice relaxation. By minimizing total-energy, the lattice constants in their ground states were determined. We discuss the total energy dependence of the volume, and density of states (DOS).

Structural and Electronic Properties of ScC and NbC: A First Principles Study

2012 ◽  
Vol 194 ◽  
pp. 276-279 ◽  
Author(s):  
Gladys Patricia Abdel Rahim ◽  
Jairo Arbey Rodríguez
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Niobium Carbide ◽  
Full Potential ◽  
Wave Method ◽  
Generalized Gradient ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Structural And Electronic Properties ◽  
Correlation Potential

We study the structural and electronic properties of scandium carbide ScC and niobium carbide NbC in both the sodium chloride rock salt (NaCl) and wurtzite structures by means of accurate first principles total energy calculations. The calculations were performed employing the full-potential linearized plane wave method (FP-LAPW). We used the generalized gradient approximation (GGA) of Perdew Burke and Ernzerhof for the exchange and correlation potential. Volume optimization and density of states including spin (DOS) of the systems are presented.

First Principle Study on Electronic Structure of Nanocrystalline BaTiO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 2510-2512
Author(s):  
Xiang Yun Deng ◽  
Long Tu Li ◽  
Xiao Hui Wang ◽  
Zhi Lun Gui
Keyword(s):  
Electronic Structure ◽  
Partial Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Augmented Plane Wave Method ◽  
Nanocrystalline Batio3 Ceramics ◽  
Linearized Augmented Plane Wave

The full potential linearized augmented plane wave method within the generalized gradient approximation was used to calculate electronic structure of nanocrystalline BaTiO3 ceramics. We calculated the total and partial density of states of 50 nm BaTiO3 ceramics. The results show that the atoms distribution of nanograin BaTiO3 ceramics is different from those of coarse BaTiO3 ceramics. It is also revealed that the hybridization between Ti 3d and O 2p is very strong, which is very important to the ferroelectric stability of nanocrystalline BaTiO3 ceramics.

SEGREGATION OF Cu IN THE Cu/Ni MULTILAYERS

2008 ◽  
Vol 22 (20) ◽  
pp. 1893-1902
Author(s):  
L. Y. LI ◽  
G. H. YU ◽  
F. W. ZHU
Keyword(s):  
Approximation Formula ◽  
Full Potential ◽  
Slab Surface ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Augmented Plane Wave Method ◽  
Linearized Augmented Plane Wave ◽  
Vacuum Effect

The segregation of Cu atoms in the Cu/Ni multilayers was investigated by means of the full-potential linearized augmented plane-wave method with the generalized-gradient approximation formula. We investigated the segregation of Cu atoms when the Cu/Ni slab is along the (001) and (111) directions, respectively. The results obtained show that at most one-layer Cu atoms can segregate to the Ni surface when Ni films are deposited on the Cu substrate and the segregation of Cu atoms is not sensitive to the orientation of the Cu/Ni slab surface. The result of Cu segregation is to reduce the vacuum effect.

First Principles Study on Structural, Electronic, Elastic and Thermal Properties of OsAl and OsSi

2014 ◽  
Vol 1047 ◽  
pp. 71-77 ◽  
Author(s):  
Nikita Acharya ◽  
Bushra Fatima ◽  
Sunil Singh Chouhan ◽  
Sankar P. Sanyal
Keyword(s):  
Thermal Properties ◽  
First Principles ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
First Principles Study ◽  
First Time ◽  
Good Agreement

First - principles study on structural, electronic, elastic and thermal properties of B2phase OsAl and OsSi have been reported usingab-initio full potential linearized plane wave method (FP-LAPW) method within generalized gradient approximation (GGA). We have calculated ground state and electronic properties such as lattice constant (a0), bulk modulus (B0), its pressure derivative (B0') and density of states at Fermi level N(EF). Lattice constants are in good agreement with other results. The elastic constants (C11, C12and C44) are also calculated for these compounds. Ductility has been analyzed by Pugh’s rule (B/GH) ratio and Cauchy’s pressure (C12-C44). To the best of our knowledge, these properties are calculated first time.

First-Principles Calculations and the Thermodynamics of Cementite

2010 ◽  
Vol 638-642 ◽  
pp. 3319-3324 ◽  
Author(s):  
Jae Hoon Jang ◽  
In Gee Kim ◽  
H.K.D.H. Bhadeshia
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Lattice Constants ◽  
Unit Cells ◽  
Linearized Augmented Plane Wave

Thermodynamic data for the substitution of silicon and manganese in cementite have been estimated using first-principles methods in order to aid the design of steels where it is necessary to control the precipitation of this phase. The need for the calculations arises from the fact that for silicon the data cannot be measured experimentally; manganese is included in the analysis to allow a comparison with its known behaviour. The calculations for Fe3C, (Fe11Si4c)C4, (Fe11Si8d)C4, (Fe11Mn4c)C4 and (Fe11Mn8d)C4 are based on the total energy all-electron full-potential linearized augmented plane-wave method within the generalized gradient approximation to density functional theory. The output includes the ground state lattice constants, atomic positions and bulk moduli. It is found that (Fe11Si4c)C4 and (Fe11Si8d)C4 have about 52 and 37 kJ greater formation energy when compared with a mole of unit cells of pure cementite, whereas the corresponding energy for (Fe11Mn4c)C4 and (Fe11Mn8d)C4 is less by about 5 kJ mol1. These results for manganese match closely with published trends and data; a similar comparison is not possible for silicon but we correctly predict that the solubility in cementite should be minimal.

FIRST-PRINCIPLES INVESTIGATION OF SnO2 AT HIGH PRESSURE

2005 ◽  
Vol 19 (27) ◽  
pp. 4081-4092 ◽  
Author(s):  
F. EL HAJ HASSAN ◽  
A. ALAEDDINE ◽  
M. ZOAETER ◽  
I. RACHIDI
Keyword(s):  
Total Energy ◽  
Density Functional ◽  
Tin Dioxide ◽  
Correlation Energy ◽  
Structural Phase ◽  
Cubic Phase ◽  
Full Potential ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation

The ground state properties and the structural phase transformation of tin dioxide ( SnO 2) have been investigated using first principle full potential-linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). We used local density approximation (LDA) and the generalized gradient approximation (GGA), which are based on exchange-correlation energy optimization, to optimize the internal parameters by relaxing the atomic positions in the force directions and to calculate the total energy. For band structure calculations, we utilized both the Engel-Vosko's generalized gradient approximation (EVGGA), which optimizes the exchange-correlation potential, and also GGA. From the obtained band structures, the electron (hole) valance and conduction effective masses are deduced. For compressed volumes SnO 2 is shown to undergo two structural phase transitions with increasing pressure from the rutile- to the CaCl 2-type phase at 12.4 GPa and to a cubic phase, space group [Formula: see text] at 22.1 GPa. The calculated total energy allowed us to investigate several structural properties, in particular, the equilibrium lattice constants, bulk modulus, cohesive energy, interatomic distances and the angles between different atomic bonds. In addition, we discuss the bonding parameter in term of charge density, which show the localization of charge around the anion side.

scholarly journals First-principles calculations of antimony sulphide Sb2S3

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Afiq Radzwan ◽  
Rashid Ahmed ◽  
Amiruddin Shaari ◽  
Abdullahi Lawal ◽  
Ying Xuan Ng
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Metal Chalcogenides ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Linearized Augmented Plane Wave

The structural, electronic and optical  properties of Sb2S3 have been investigated  using full-potential linearized augmented plane wave method within density functional theory (DFT) framework, treating exchange-correlation potential with Engel-Vosko generalized gradient approximation (EV-GGA). Electronic properties calculations were performed  with and without taken into account the effects of spin-orbit coupling (SOC) . From our results we found that structural properties,density of states and band structure are in good agreement with experimental results.The effects of SOC and relativistic on electronic properties were found to be negligible. However, optical properties, namely, imaginary and real parts of dielectric function, reflectivity, absorption coefficient, refractive index, extinction coefficient and energy loss function were calculated and analyized.Optical gap of 1.61 eV proves that Sb2S3 metal chalcogenides is a promising material for solar cell device.

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.

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