Electronic structure, magnetism and stability of Co2CrX (X =Al, Ga, In) ab initio study

2016 ◽  
Vol 30 (01) ◽  
pp. 1550265 ◽  
Author(s):  
F. Dahmane ◽  
D. Mesri ◽  
A. Tadjer ◽  
R. Khenata ◽  
S. Benalia ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Type Structure ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Good Convergence ◽  
Structure Calculations ◽  
Full Heusler

The structural, electronic as well as the magnetic properties of the Co2CrX (X[Formula: see text]Al, Ga and In) full-Heusler alloy have been studied using first-principles calculations performed in the framework of density functional theory (DFT) within the generalized gradient approximation (GGA). It was taken into account both possible L21 structures (i.e. Hg2CuTi- and Cu2MnAl-type). Basically, for all compounds, the Cu2MnAl-type structure is energetically more stable than Hg2CuTi-type structure at the equilibrium volume. The electronic structure calculations for Co2CrAl reveal that half-metallic (HM) character in Cu2MnAl-type structure, Co2CrGa show nearly HM behavior and Co2CrIn has a metallic character. The predicted total magnetic moment is [Formula: see text] for Co2CrX (X[Formula: see text]Al, Ga) which is in good convergence with the Slater–Pauling (SP) rule.

Electronic structure of cubic BaTbO3 from first-principles pseudopotential calculations

2006 ◽  
Vol 84 (2) ◽  
pp. 115-120 ◽  
Author(s):  
G Y Gao ◽  
K L Yao ◽  
Z L Liu
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Pseudopotential Calculations ◽  
Correlation Potential ◽  
Density Contour

First-principles calculations of the electronic structure are performed for cubic BaTbO3 using the plane-wave pseudopotential method within the framework of density functional theory and using the generalized gradient approximation for the exchange-correlation potential. Our calculations show that cubic BaTbO3 is metallic, and that this metallic character is mainly governed by the Tb 4f electrons and the hybridization between the Tb 5d and O 2p states. From the analysis of the density of states, band structure, and charge density contour, we find that the chemical bonding between Tb and O is covalent while that between Ba and TbO3 is ionic. PACS Nos.: 71.15.Mb, 71.20.-b

Theoretical Characterization of Thermodynamic, Magnetic and Electronic Proprieties of Full-Heusler Co2YGa (Y = V, Cr and Mn) Alloys

SPIN ◽  
2020 ◽  
Vol 10 (01) ◽  
pp. 2050005
Author(s):  
M. Mokhtari ◽  
D. Amari ◽  
F. Dahmane ◽  
G. Benabdellah ◽  
L. Zekri ◽  
...  
Keyword(s):  
Density Functional ◽  
Heusler Alloys ◽  
Debye Model ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Lattice Constants ◽  
Full Heusler ◽  
Good Agreement

The electronic structure, magnetism and thermal proprieties of the full-Heusler alloys Co2YGa (Y [Formula: see text] V, Cr and Mn) have been investigated by first-principles calculations based on density functional theory with the generalized gradient approximation (GGA). Our obtained results of lattice parameters show reasonable agreement to the previously reported experimental and other theoretical studies. The calculations show that all Co2YGa (Y [Formula: see text] V, Cr and Mn) alloys belong to half-metallic compound with a magnetic moment of 2.00, 3.00 and 4.00 [Formula: see text] at their respective equilibrium lattice constants which is in good agreement with the Slater–Pauling rule and perfect 100% spin polarization at the Fermi level. The thermal effect on the macroscopic properties of these alloys is presented such as the thermal expansion coefficient, heat capacity and Debye temperature, based on the quasi-harmonic Debye model.

scholarly journals Prediction of electronic and half metallic properties of Mn2YSn (Y = Mo, Nb, Zr) Heusler alloys

2021 ◽  
Vol 24 (1) ◽  
pp. 13703
Author(s):  
S. Zeffane ◽  
M. Sayah ◽  
F. Dahmane ◽  
M. Mokhtari ◽  
L. Zekri ◽  
...  
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Type Structure ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Lattice Constants ◽  
Good Agreement

We investigate the structural, electronic and magnetic properties of the full Heusler compounds Mn2YSn (Y = Mo, Nb, Zr) by first- principles density functional theory using the generalized gradient approximation. It is found that the calculated lattice constants are in good agreement with the theoretical values. We observe that the Cu2MnAl-type structure is more stable than the Hg2CuTi type. The calculated total magnetic moments of Mn2NbSn and Mn2ZrSn are 1 μB and 2 μB at the equilibrium lattice constant of 6.18 Å and 6.31 Å, respectively, for the Cu2MnAl-type structure. Mn2MoSn have a metallic character in both Hg2CuTi and Cu2MnAl type structures. The total spin magnetic moment obeys the Slater-Pauling rule. Half-metal exhibits 100% spin polarization at the Fermi level. Thus, these alloys are promising magnetic candidates in spintronic devices.

Mechanical and Electronic Properties of P42/mnm Silicon Carbides

2016 ◽  
Vol 71 (5) ◽  
pp. 387-396 ◽  
Author(s):  
Quan Zhang ◽  
Qun Wei ◽  
Haiyan Yan ◽  
Qingyang Fan ◽  
Xuanmin Zhu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Silicon Carbides ◽  
Structure Calculations

AbstractTwo new phases of Si8C4 and Si4C8 with the P42/mnm symmetry are proposed. Using first principles calculations based on density functional theory, the structural, elastic, and electronic properties of Si8C4 and Si4C8 are studied systematically. Both Si8C4 and Si4C8 are proved to be mechanically and dynamically stable. The elastic anisotropies of Si8C4 and Si4C8 are studied in detail. Electronic structure calculations show that Si8C4 and Si4C8 are indirect semiconductors with the band gap of 0.74 and 0.15 eV, respectively.

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.

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

scholarly journals Oxygen vacancy and doping atom effect on electronic structure and optical properties of Cd2SnO4

RSC Advances ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 640-646 ◽  
Author(s):  
Mei Tang ◽  
JiaXiang Shang ◽  
Yue Zhang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
La Doped ◽  
Doping Atom ◽  
Atom Effect

The electronic structure and optical properties of oxygen vacancy and La-doped Cd2SnO4 were calculated using the plane-wave-based pseudopotential method based on the density functional theory (DFT) within the generalized gradient approximation (GGA).

First-principles study of static displacements in Fe-Pd magnetic shape-memory alloys

2009 ◽  
Vol 1200 ◽  
Author(s):  
Markus E. Gruner
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Magnetic Shape Memory ◽  
Magnetic Shape Memory Alloys ◽  
Functional Theory ◽  
Lennard Jones ◽  
Theory Comparison

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.

Identifying the catalytically active sites on the layered tri-chalcogenide compounds CoPS3 and NiPS3 for efficient hydrogen evolution reaction

2021 ◽  
Author(s):  
Khorsed Alam ◽  
Tisita Das ◽  
Sudip Chakraborty ◽  
Prasenjit Sen
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Functional Theory ◽  
Catalytically Active ◽  
Structure Calculations

Electronic structure calculations based on density functional theory are used to identify the catalytically active sites for the hydrogen evolution reaction on single layers of the two transition metal tri-chalcogenide...

Electronic Structure and Ferromagnetic Properties of Doped Calcium Sulfide Ca1−xTMxS (TM = V, Cr and Co)

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050013 ◽  
Author(s):  
Amina Aiche ◽  
Abdelkader Tadjer ◽  
Hadj Moulay Ahmed Mazouz ◽  
Bendouma Doumi ◽  
Houari Khachai
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Double Exchange ◽  
Ferromagnetic State ◽  
Spin Splitting ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Half Metallic

The electronic structure and magnetic properties of diluted Ca[Formula: see text]TMxS (TM[Formula: see text][Formula: see text][Formula: see text]V, Cr and Co) in the rocksalt structure at concentrations [Formula: see text], 0.125 and 0.25 were studied using the full-potential linearized augmented plane wave approximation of the density functional theory with the Wu-Cohen generalized gradient approximation (WC-GGA) and the Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential. Features such as lattice constant, bulk modulus, spin-polarized band structures, total and local densities of states and magnetic properties have been computed. The electronic structure show that Ca[Formula: see text](V, Cr)xS at all the studied concentrations and the diluted Ca[Formula: see text]CoxS with [Formula: see text] compounds are half-metallic ferromagnets with spin polarization of 100%. The calculated total magnetic moments for Ca[Formula: see text]VxS and Ca[Formula: see text]CoxS show the same integer value of 3[Formula: see text][Formula: see text] per formula unit and Ca[Formula: see text]CrxS exhibit a total magnetic moment of 4[Formula: see text][Formula: see text], which confirm the half-metallic behavior of these compounds. We also calculated the values of the band edge spin splitting of the valence and conduction bands and the exchange constants. We have found that the ferromagnetic state is stable by the p-d exchange associated with the double-exchange mechanism. The diluted Ca[Formula: see text](V,Cr,Co)xS are found to be new promising candidates for spintronic applications.

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