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.

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.

scholarly journals Theoretical Investigations on the Mechanical, Magneto-Electronic Properties and Half-Metallic Characteristics of ZrRhTiZ (Z = Al, Ga) Quaternary Heusler Compounds

2019 ◽  
Vol 9 (5) ◽  
pp. 883 ◽  
Author(s):  
Wenbin Liu ◽  
Xiaoming Zhang ◽  
Hongying Jia ◽  
Rabah Khenata ◽  
Xuefang Dai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Total Magnetic Moment ◽  
Heusler Compounds ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Theoretical Investigations ◽  
Valence Electrons

The electronic, magnetic, and mechanical properties were investigated for ZrRhTiZ (Z = Al, Ga) quaternary Heusler compounds by employing first-principles calculations framed fundamentally within density functional theory (DFT). The obtained electronic structures revealed that both compounds have half-metallic characteristics by showing 100% spin polarization near the Fermi level. The half-metallicity is robust to the tetragonal distortion and uniform strain of the lattice. The total magnetic moment is 2 μB per formula unit and obeys the Slater-Pauling rule, Mt = Zt − 18 (Mt and Zt represent for the total magnetic moment and the number of total valence electrons in per unit cell, respectively). The elastic constants, formation energy, and cohesive energy were also theoretically calculated to help understand the possibility of experimental synthesis and the mechanical properties of these two compounds.

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.

THE FIRST PRINCIPLES CALCULATION OF STRUCTURAL, ELECTRONIC AND MAGNETIC PROPERTIES OF MnXY (X = Ru, Rh AND Y = Ga, Ge, Sb) ALLOYS

2011 ◽  
Vol 25 (26) ◽  
pp. 2079-2090 ◽  
Author(s):  
S. M. MONIRI ◽  
Z. NOURBAKHSH ◽  
M. MOSTAJABODAAVATI
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Local Magnetic Moment ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Half Metallic ◽  
Electronic And Magnetic Properties

The structural, electronic and magnetic properties of MnXY ( X = Ru , Rh and Y = Ga , Ge , Sb ) Heusler alloys are studied using density functional theory by the WIEN2k package. These materials are ferromagnetic. Also they have some interesting half-metallic properties. The electron density of states, total and local magnetic moment of these alloys are calculated. We have calculated the effective Coulomb interaction U eff using the ab initio method. We have compared the magnetic moments of these alloys in GGA and LDA + U with the Slater–Pauling rule. Furthermore the effect of hydrostatic pressure on the magnetic moment of these alloys is studied. The calculated results are fitted with a second order polynomial.

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.

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.

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.

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.

STRUCTURE AND MAGNETIC PROPERTIES OF Co12X(X = Ni, Ag, Pt, Au) CLUSTERS

2007 ◽  
Vol 21 (30) ◽  
pp. 5091-5098 ◽  
Author(s):  
Q. L. LU ◽  
J. C. JIANG ◽  
J. G. WAN ◽  
G. H. WANG
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Stable Configuration ◽  
Many Body ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Au Clusters ◽  
The Density Functional Theory ◽  
Ground State Structures ◽  
Body Potential

The ground state structures of Co 12 X ( X = Ni , Ag , Pt , Au ) clusters are obtained by a genetic algorithm with a Gupta-like many-body potential, and further optimized using the density functional theory with generalized gradient approximation. The structures of Co 12 X have a slightly distorted icosahedral pattern. The X atom is on the surface for the most stable configuration. Their total magnetic moments are 0μ B , 3μ B , 21μ B , and 22μ B , respectively. The reasons for the reduction of magnetism of Co 12 X are discussed in detail.

Ab Initio Study the Transport Properties of Alumium-Phosphorus Dopped Si Atomic Nanowire

2011 ◽  
Vol 391-392 ◽  
pp. 1128-1131
Author(s):  
You Lin Peng ◽  
Yan Hong Zhou ◽  
Li Li Zhou
Keyword(s):  
Transport Properties ◽  
Silicon Atom ◽  
Density Functional ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Pure Silicon ◽  
The Third ◽  
Current Voltage ◽  
The Density Functional Theory ◽  
The Wire

We perform first-principles calculation of the transport properties of alumium-phosphorus dopped Si atomic nanowire coupled to two Al(100) nanoscale electrodes using the non-equilibrium Green formalism combined with the density-functional theory. In particular, the alumium-phosphorus dopped silicon wire with seven atoms sandwiched between the Al(100) electrodes is considered. It is found that the transport properties are sensitive to the dopping position of the alumium and the phosphorus on the silicon wire. The equilibrium conductance of the pure silicon wire is rather big, close to 3 G0, Three eigenchannels which contribute to the equilibrium conductance are fully open. All cases of the alumium-phosphorus dopping reduce the conductivity of the pure silicon wire. In particular, the conductance of the wire decreases to 0.7 G0 when a phosphorus substitutes the third silicon atom and a alumium substitutes the sixed silicon atom. The current-voltage(I-V) curves of these cases vary dramatically. The current across the wire with a phosphorus substitutes the third silicon atom and a alumium substitutes the sixed silicon atom is rather smaller than the that across the pure silicon. A detailed analysis of the transmission coefficient of the eigenchannels, the projected density of states are made to reveal the mechanism of the differences.

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