ELECTRONIC STRUCTURE AND MAGNETIC PROPERTIES OF Co2YZ(Y = Cr, Z = Al, Ga) TYPE HEUSLER COMPOUNDS: A FIRST PRINCIPLE STUDY

2012 ◽  
Vol 26 (08) ◽  
pp. 1250071 ◽  
Author(s):  
D. P. RAI ◽  
A. SHANKAR ◽  
SANDEEP ◽  
M. P. GHIMIRE ◽  
R. K. THAPA
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Magnetic Moments ◽  
Full Potential ◽  
Local Spin Density Approximation ◽  
Heusler Compounds ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Augmented Plane Wave ◽  
3D Elements

The structural optimization was followed by the calculation of electronic structure and magnetic properties on Co 2 CrAl and Co 2 CrGa . The structure optimization was based on generalized gradient approximation (GGA). The calculation of electronic structure was based on full potential linear augmented plane wave (FPLAPW) method within local spin density approximation (LSDA). We studied the electronic structure and magnetic properties. Results of density of states (DOS) and band structures shows that Co 2 CrAl and Co 2 CrGa are half-metallic ferromagnets (HMFS). The calculated magnetic moments of Co 2 CrAl and Co 2 CrGa are 2.915 and 3.075 μ B , respectively. We have calculated the onsite d–d coulomb and exchange interaction (U) For 3d elements like Co and Cr . The strongly localized d states were treated with LSDA+U method.

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.

FIRST PRINCIPLES STUDY OF ELECTRONIC STRUCTURE AND MAGNETIC PROPERTIES OF HALF-METALLIC FULL-HEUSLER ALLOYS Co2MnSi and Co2FeSi

2010 ◽  
Vol 24 (08) ◽  
pp. 967-978 ◽  
Author(s):  
JINGSHAN QI ◽  
HAILIN YU ◽  
XUEFAN JIANG ◽  
DANING SHI
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Lattice Parameters ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Half Metallic

We present a comprehensive investigation of the equilibrium structural, electronic and magnetic properties of C o2 MnSi and C o2 FeSi by density-functional theory (DFT) within the generalized gradient approximation (GGA) using the projected augmented wave (PAW) method. The on-site Coulomb interaction has also taken into account ( GGA +U) approach to unravel the correlation effects on the electronic structure. The change of the energy gap, "spin gap", Fermi energy level and magnetic moments with the lattice parameters is investigated. We found that the on-site correlation interaction in C o2 FeSi is stronger than in C o2 MnSi . So on-site electronic correlation is necessary for C o2 FeSi and the magnetic moments reproduce experimental results well by GGA +U. Further we also found that a moderate change of the lattice parameters does not change the half-metallic ferromagnet (HMF) behavior for both materials. Appearance of half-metallicity is consistent with the integral magnetic moments, which also agrees with the experiment measurements.

A First Principle Calculation of Full-Heusler Alloy Co2TiAl: LSDA+U Method

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
D. P. Rai ◽  
R. K. Thapa
Keyword(s):  
Electronic Structure ◽  
Plane Wave ◽  
Full Potential ◽  
Local Spin Density Approximation ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Calculated Density ◽  
Augmented Plane Wave ◽  
First Principle Calculation ◽  
The Impact

We performed the structure optimization of Co2TiAl based on the generalized gradient approximation (GGA) and linearized augmented plane wave (LAPW) method. The calculation of electronic structure was based on the full-potential linear augmented plane wave (FP-LAPW) method and local spin density approximation exchange correlation LSDA+U. We also studied the impact of the Hubbard potential or onsite Coulomb repulsion (U) on electronic structure; the values are varied within reasonable limits to study the resulting effect on the physical properties of Co2TiAl system. The calculated density of states (DOS) shows that half-metallicity of Co2TiAl decreases with the increase in U values.

Half-metallic ferromagnetism in V-doped ZnTe semiconductor at reduced dopant concentration

2014 ◽  
Vol 28 (13) ◽  
pp. 1450104 ◽  
Author(s):  
M. Sajjad ◽  
H. X. Zhang ◽  
N. A. Noor ◽  
S. M. Alay-e-Abbas ◽  
M. Abid ◽  
...  
Keyword(s):  
Density Functional ◽  
Spin Exchange ◽  
Density Functional Theory Calculations ◽  
Orbital Method ◽  
Ferromagnetic Behavior ◽  
Full Potential ◽  
Local Spin Density Approximation ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Bonding Properties

In this study, we examine the structural, electronic, magnetic and bonding properties of zincblende phase Zn 1-x V x Te (x = 0.0625, 0.125, 0.25) compounds to present them as suitable candidates for spintronic applications. Density functional theory calculations have been used by implementing the accurate full-potential linear-augmented-planewave plus local-orbital method. Structural properties have been computed using Wu–Cohen generalized gradient approximation, whereas the modified Becke and Johnson local (spin) density approximation (mBJLDA) function has been employed for the evaluating ground state electronic properties and ferromagnetic behavior. The half-metallic (HM) ferromagnetism in Zn 1-x V x Te is analyzed in terms of V -3d states and it is shown that mBJLDA predicts wide HM gaps which promise the possibility of achieving V -doped ZnTe with high Curie temperature. The spin exchange splittings Δx(d) and Δx(pd) have been estimated and the contribution of conduction band (CB) and valence band (VB) in exchange splitting is calculated in terms of the exchange constants N0α and N0β. Furthermore, spin-polarized charge density calculation is presented for elucidating the bonding nature, while pressure dependence of total magnetic moment for three concentrations of V -doped ZnTe is also discussed.

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.

Structural, Electronic and Magnetic Properties of CaSe Doped with 3d (V, Cr and Mn)

SPIN ◽  
2021 ◽  
Author(s):  
Youcef Daoudi ◽  
Hadj Moulay Ahmed Mazouz ◽  
Brahim Lagoun ◽  
Ali Benghia
Keyword(s):  
Magnetic Properties ◽  
Transition Metal ◽  
Density Functional ◽  
Magnetic Moments ◽  
Plane Waves ◽  
Double Exchange ◽  
Spin Splitting ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic And Magnetic Properties

We report first-principles investigation on structural, electronic and magnetic properties of 3d transition metal element-doped rock-salt calcium selenide Ca[Formula: see text]TMxSe (TM = V, Cr and Mn) at concentrations [Formula: see text] = 0.0625, 0.125 and 0.25. We performed the calculations in the framework of the density functional theory (DFT) using the full-potential linearized augmented plane waves plus local orbitals (FP-LAPW+lo) method within the Wu–Cohen generalized gradient approximation (WC-GGA) for the structural optimization and the Tran–Blaha modified Becke–Johnson (TBmBJ) potential for the electronic and the magnetic properties. The computed spin-polarized band structures and densities of states show that Ca[Formula: see text]CrxSe compounds at all studied concentrations are half-metallic ferromagnets with a complete spin polarization of 100% at Fermi-level while the Ca[Formula: see text]VxSe and Ca[Formula: see text]MnxSe are ferromagnetic semiconductors. The total magnetic moments for Ca[Formula: see text]VxSe, Ca[Formula: see text]CrxSe, and Ca[Formula: see text]MnxSe show the integer values of 3[Formula: see text][Formula: see text], 4[Formula: see text][Formula: see text], and 5[Formula: see text][Formula: see text], respectively, with a major contribution of transition metal elements (TM) in the total magnetization. Also, we reported the calculated exchange constants [Formula: see text] and [Formula: see text] and the band edge spin splitting of the valence ([Formula: see text]) and conduction ([Formula: see text]) bands. The ferromagnetism of these compounds is due to the super-exchange and the double-exchange mechanisms in addition to the strong p–d exchange interaction. Therefore, the predicted results indicate that the diluted Ca[Formula: see text]TMxSe (TM = V, Cr, Mn) compounds are suitable candidates for a possible application in the field of spintronic technology.

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.

Theoretical study of structural, electronic and magnetic properties of equiatomic quaternary CoPdCrZ (Z = Si, Ge, P) Heusler alloys

2019 ◽  
Vol 33 (31) ◽  
pp. 1950389 ◽  
Author(s):  
Hafsa Arshad ◽  
M. Zafar ◽  
S. Ahmad ◽  
M. Rizwan ◽  
M. I. Khan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Full Potential ◽  
Type I ◽  
Augmented Plane Wave ◽  
Half Metals ◽  
Electronic And Magnetic Properties ◽  
Quaternary Heusler Alloys ◽  
Linearized Augmented Plane Wave

In this study, the structural, electronic and magnetic properties of Co-based equiatomic quaternary Heusler alloys (EQHA) CoPdCrZ (Z = Si, Ge, P) are investigated by full potential linearized augmented plane wave (FP-LAPW) method. Three different configurations are employed to find out the most stable structure by structural optimization process. The alloys CoPdCrSi and CoPdCrGe are found to be stable in Type-II structure while CoPdCrP is in Type-I. The calculated electronic and magnetic properties show that CoPdCrSi and CoPdCrGe are nearly half metals while CoPdCrP is a ferromagnetic alloy. By following the Slater–Pauling rule [Formula: see text], the total magnetic moments are calculated. The spin polarization and Curie temperature have also been calculated.

Band Structure and Optical Properties of CuInSe2

2014 ◽  
Vol 894 ◽  
pp. 254-258
Author(s):  
Rong Zhen Chen ◽  
Clas Persson
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Coupling Effect ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

In this work, the electronic structure and dielectric function of chalcopyrite CuInSe2 are presented. The results are based on the full-potential linearized augmented plane wave (FPLAPW) method using the generalized gradient approximation (GGA) plus an onsite Coulomb interaction U of the Cu d states. The dielectric constant, absorption coefficient and refractive index are explored by means of optical response. The spin-orbit coupling effect is considered for the calculations of electronic structure and optical properties. We find that the results based on our calculation method have good agreement compared with experimental and other earlier simulations results.

FIRST-PRINCIPLES STUDY OF THE EFFECTS OF THE OXYGEN VACANCY ON ELECTRONIC STRUCTURE AND FERROMAGNETISM OF Sn2 Co2O8-δ

2010 ◽  
Vol 24 (14) ◽  
pp. 2229-2235
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
HANLIE HONG ◽  
MIAO WAN ◽  
GUANGFU JI
Keyword(s):  
Electronic Structure ◽  
Oxygen Vacancy ◽  
Magnetic Moment ◽  
First Principles ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Spin Magnetic Moment ◽  
Metallic Behavior ◽  
Half Metallic ◽  
Single Oxygen

The electronic structure and ferromagnetism of Sn 2 Co 2 O 8 and Sn 2 Co 2 O 7 have been investigated based on the first-principles plane-wave pseudopotential method within the generalized gradient approximation. The calculated results reveal that the oxygen vacancy plays an important role in the electronic structure and ferromagnetism. The Sn 2 Co 2 O 8 shows half-metallic behavior, but by introducing single oxygen vacancy, the half-metallic transits to metallic behavior. At the same time, the spin magnetic moment of every Co atom and the total magnetic moment change greatly. For Sn 2 Co 2 O 8 and Sn 2 Co 2 O 7, the total spin magnetic moments are 1.99 and 3.49 uB, respectively.

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