Electronic Structure and Magnetic Properties of Ga-Doped Heusler Alloy Co2FeSi

2011 ◽  
Vol 130-134 ◽  
pp. 1430-1434 ◽  
Author(s):  
Yu Feng ◽  
Bo Wu ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Doping Concentration ◽  
Magnetic Moments ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
Lattice Constants ◽  
The Density Functional Theory

Using GGA+U (UCo=2.1eV, UFe=2.5eV) scheme based on the density functional theory (DFT), we investigate the electronic structure, magnetism and half-metallic stability of Ga-doped Heusler compound Co2FeSi. We find that the lattice constants and total magnetic moments in per unit respectively obey the Vegard’s rule and the Slater-Pauling rule well. The most stable half-metallicity occurs at doping concentration x=0.5 due to the Fermi level is situated slightly above the middle of the spin-down gap. Our studies also indicate that the RKKY-type exchange mechanism plays a dominating role in determining the magnetism of HMFs.

Tunable Magnetism and Half-Metallic Stability of Half-Heusler Compound NiMn1-xNbxSb

2011 ◽  
Vol 415-417 ◽  
pp. 1407-1410
Author(s):  
Qing Zhou ◽  
Bo Wu ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Magnetic Coupling ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
Lattice Constants ◽  
The Density Functional Theory

By using the first-principles calculations within the density functional theory (DFT), we investigate the electronic structure, magnetism and half-metallic stability of half-Heusler compound NiMn1-xNbxSb. The results showed that the lattice constants and magnetic moments per unit respectively follow the Vegard law and the Slater-Pauling rule well. The most stable half-metallicity occurs at doping concentration x=0.25 due to the Fermi level is situated the middle of the spin-down gap. Our studies also indicate that the competition of hybridization of d-electrons and RKKY-type magnetic coupling plays a dominating role in determining the magnetism.

Tunable Magnetism and Half-Metallic Stability in Si-Doped Hg2CuTi-Type Ti2CoGa Alloy

2012 ◽  
Vol 229-231 ◽  
pp. 130-133 ◽  
Author(s):  
Bo Wu ◽  
Yu Feng ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Lattice Constants ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Si Doped ◽  
Direct Hybridization

Using the ab-initio calculations within the density functional theory (DFT), we have investigated the electronic structure, magnetism and half-metallic stability of Si-doped Heusler compound Ti2CoGa with Hg2CuTi-type structure. The results revel that the lattice constants and total magnetic moments in per unit obey the Vegard’s rule and the Slater-Pauling rule well, respectively. The most stable half-metallicity occurs at doping concentration x=0.75 because the Fermi level is located at the middle of the spin-minority gap. 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.

Pressure-Induced Tunable Magnetism and Half-Metallic Stability in Co2FeGa Heusler Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1303-1306
Author(s):  
Qin Xiang Gao
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Density Functional ◽  
High Energy ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
The Density Functional Theory

Using the first-principles calculations within the density functional theory (DFT), we have investigated the structure, magnetism and half-metallic stability of Co2FeGa Heusler compound under pressure from 0 to 50GPa. The results revel that the lattice constant is gradually shrank and total magnetic moment in per unit slightly decreased with increasing pressure, respectively. Moreover, with the increase of the pressure, the Fermi level will move towards high-energy orientation. When the pressure reaches at 30GPa the most stable half-metallicity is observed which the Fermi level is located at the middle of the spin-minority gap.

DFT study of elastic, half-metallic and optical properties of Co2V(Al, Ge, Ga and Si) compounds

2017 ◽  
Vol 31 (14) ◽  
pp. 1750109 ◽  
Author(s):  
Heidar Khosravi ◽  
Arash Boochani ◽  
Golnaz Rasolian ◽  
Shahram Solaymani ◽  
Sirvan Naderi
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Elastic Stability ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Spin Mode ◽  
Half Metallic ◽  
Lattice Constants ◽  
Optical Treatment

First-principles study of elastic, electronic and optical properties of full-Heusler Co2V(Al, Ge, Ga and Si) compounds are calculated through density functional theory (DFT) to obtain and compare the mentioned properties. Equilibrium lattice constants of these compounds are in good agreement with other works. Electronic calculations are shown full spin polarization at Fermi level for all compounds, so in the down spin, indirect bandgap is calculated as 0.33, 0.6, 0.2 and 0.8 eV for Co2V(Al, Ge, Ga and Si), respectively. The integer amounts of the magnetic moments are compatible with Slater–Pauling role. The optical treatment of Co2VGa is different from three other compounds. All mentioned compounds have metallic behavior by 22 eV plasmonic frequency. The imaginary part of the dielectric function for the up spin indicates that the main optical transitions occurred in this spin mode. Moreover, the elastic results show that the Co2VGa does not have elastic stability, but the other three compounds have fully elastic stability and the Co2V(Al, Ge and Si) belong to the hardness of materials.

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.

Effects of vanadium impurity on TiO2 properties

2015 ◽  
Vol 29 (15) ◽  
pp. 1550094 ◽  
Author(s):  
Arvids Stashans ◽  
Jairo Escobar
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Of States ◽  
Density Functional ◽  
Magnetic Moments ◽  
Equilibrium Geometry ◽  
Dft Studies ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Atomic Rearrangement

Our present work is based on the density functional theory (DFT) studies of TiO 2 crystals doped with V impurities. Both rutile and anatase structures have been considered within the present research and different defect concentrations have been used as well. Our calculations reveal equilibrium geometry of the system showing atomic rearrangement around the point defect being mainly inward with respect to the impurity. Magnetism and electronic structure based on the density of states (DOS) patterns for both rutile and anatase crystals have been obtained and discussed in detail. It is shown that local magnetic moments arise mainly from the 3d states of the impurity atom with some admixture of 2p states from the vanadium-nearest O atoms.

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.

scholarly journals Electronic, magnetic and optical properties of XScO3 (X=Mo, W) perovskites

2021 ◽  
Vol 3 ◽  
pp. e15
Author(s):  
Amall Ahmed Ramanathan ◽  
Jamil Mahmoud Khalifeh
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Full Potential ◽  
Functional Theory ◽  
Half Metallic ◽  
Augmented Plane Wave ◽  
Half Metals ◽  
Minority Spin ◽  
The Density Functional Theory ◽  
Linearized Augmented Plane Wave

The density functional theory (DFT) full potential linearized augmented plane wave (FP-LAPW) method with the modified Becke–Johnson (mBJ) approximation is used to perform spin polarised calculations of the transition metal perovskites MoScO3 and WScO3. Both depict half metallic behaviour with semiconducting and metallic in the minority and majority spins respectively. MoScO3 and WScO3 have indirect R− Γ band gaps in the minority spin channels of 3.61 and 3.82 eV respectively. Moreover, they both show substantial integer magnetic moments of 3μB with 100% spin polarization typical to half metals. In addition, we calculate the dielectric function, optical conductivity and the optical constants, namely, the refractive index, the reflectivity, the extinction and absorption coefficients.

scholarly journals First principles calculation of Manganese based half Heusler compounds

2020 ◽  
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
First Principles Calculation ◽  
Heusler Compounds ◽  
Functional Theory ◽  
Diverse Range ◽  
Half Metallic ◽  
The Density Functional Theory ◽  
Valence Electrons ◽  
Small Band

The Half-Heusler compounds exhibit a diverse range of tuneable properties including half-metallic ferromagnetism topological insulator, solar cells and thermoelectric converters. We have studied four half-Heusler compounds MnFeIn, MnFeGa, MnNiAs and MnNiSb. The nature and properties of half-heusler compounds can be studied on the bases of their valance electron count. In this paper, Fe based compounds have 18 valence electrons; whereas 22 valence electrons in Ni based. The Density Functional Theory (DFT) has been performed with WIEN2k code. Ni based compounds with Mn located at octahedral sites are half-metals as revealed from the Density of States (DoS) and band structure calculations. In all of them, spin-up channels are conducting; whereas in MnNiAs and MnNiSb spin-down channels have the small band gaps. MnNiAs and MnNiSb exhibit half-metallic property with integer magnetic moments of 4 μB per formula unit and half-metallic gaps of 0.15 and 0.17 eV at their equilibrium volume respectively.

scholarly journals First-Principles Study of Mechanical and Thermodynamic Properties of Binary and Ternary CoX (X = W and Mo) Intermetallic Compounds

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1404
Author(s):  
Yunfei Yang ◽  
Changhao Wang ◽  
Junhao Sun ◽  
Shilei Li ◽  
Wei Liu ◽  
...  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Vibrational Entropy ◽  
Functional Theory ◽  
Lattice Constants ◽  
The Density Functional Theory ◽  
Ductile Behavior ◽  
Pseudo Potential

In this study, the structural, elastic, and thermodynamic properties of DO19 and L12 structured Co3X (X = W, Mo or both W and Mo) and μ structured Co7X6 were investigated using the density functional theory implemented in the pseudo-potential plane wave. The obtained lattice constants were observed to be in good agreement with the available experimental data. With respect to the calculated mechanical properties and Poisson’s ratio, the DO19-Co3X, L12-Co3X, and μ-Co7X6 compounds were noted to be mechanically stable and possessed an optimal ductile behavior; however, L12-Co3X exhibited higher strength and brittleness than DO19-Co3X. Moreover, the quasi-harmonic Debye–Grüneisen approach was confirmed to be valid in describing the temperature-dependent thermodynamic properties of the Co3X and Co7X6 compounds, including heat capacity, vibrational entropy, and Gibbs free energy. Based on the calculated Gibbs free energy of DO19-Co3X and L12-Co7X6, the phase transformation temperatures for DO19-Co3X to L12-Co7X6 were determined and obtained values were noted to match well with the experiment results.

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