scholarly journals Первопринципное иследование полуметаллических свойств сплавов Гейслера Mn-=SUB=-2-=/SUB=-ScZ (Z=Al, Si, P, Ga, Ge, As, In, Sn, Sb)

2021 ◽  
Vol 63 (11) ◽  
pp. 1751
Author(s):  
Д.Р. Байгутлин ◽  
В.В. Соколовский ◽  
О.Н. Мирошкина ◽  
В.Д. Бучельников
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Heusler Alloys ◽  
Metallic State ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Exchange Correlation ◽  
The Density Functional Theory

The properties of Heusler alloys of the Mn2ScZ family (Z = Al, Si, P, Ga, Ge, As, In, Sn, Sb) are investigated within the framework of the density functional theory. The PBE GGA and meta-GGA SCAN functionals were used for approximation of the exchange-correlation interactions. Calculations show that PBE does not predict ideal half-metallic behavior, unlike SCAN. It is shown that at Z = P, Si, a transition from the half-metallic state to the metallic one is observed. This effect can be used to develop tunable spintronic devices.

scholarly journals Theoretical Study of the Electronic Properties of X2YZ (X = Fe, Co; Y = Zr, Mo; Z = Ge, Sb) Ternary Heusler: Abinitio Study

2020 ◽  
Vol 62 (1) ◽  
pp. 1-14
Author(s):  
A. Maafa ◽  
H. Rozale ◽  
A. Oughilas ◽  
A. Boubaça ◽  
A. Amar ◽  
...  
Keyword(s):  
Density Functional ◽  
Heusler Alloys ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Half Metals ◽  
Potential Applications ◽  
Small Band ◽  
Moderate Range

AbstractIn the purpose of exploring new Heusler alloys with different magnetic applications, we have employed first principles calculations method within density functional theory. After checking the structural stability of X2YZ Heusler alloys (X = Fe, Co; Y =Zr, Mo and Z = Ge, Sb), we found that Cu2MnAl type structure is more favorable for most compounds except for X2MoGe and Co2MoSb, were the Hg2CuTi structure is energetically more stable. The trends in magnetic and electronic structures can be predicted by the structure types as well as the different kinds of hybridizations between the constituents. Among the two series only two compounds were identified to be true half metals with potential applications in spintronic devices. While one compound was classified as a nonmagnetic semiconductor with a small band gap. For the rest of materials, we found that the metallic behavior is dominant. These materials show possible interesting features in technical applications as well. The effect of distortion on the magnetic properties of Co2ZrGe and Fe2ZrSb showed that the half metallic character was preserved within a moderate range of volume changes, which makes it possible to grow these materials as thin films with modern techniques.

scholarly journals The surface effect on the thermodynamic stability, half-metallic and optical properties of Co2MnGa(001) films: a DFT study

2019 ◽  
Vol 9 (4) ◽  
pp. 339-348
Author(s):  
R. Ashtari Faregh ◽  
A. Boochani ◽  
S. R. Masharian ◽  
F. H. Jafarpour
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Stability ◽  
Density Functional ◽  
Surface Effect ◽  
Optical Parameters ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Half Metallic ◽  
The Density Functional Theory ◽  
Full Heusler

Abstract In this study, the half-metallic properties, thermodynamic stability and optical parameters of the full-Heusler Co2MnGa compound and its four different terminations of Co–Co, Co–Mn, Mn–Ga and Co–Ga from the surface of Co2MnGa (001) have been calculated based on the density functional theory (DFT). The results confirm the ferromagnetic half-metallic behavior with a magnetic moment of 4.08 $$ \mu_{\text{B}} $$μB and a gap of 0.32 eV at the Fermi level of Co2MnGa bulk phase having a Cu2MnAl-type structure. The density of states curves showed that all possible terminations from the Co2MnGa (001) surface eliminate the half-metallic behavior except the termination of Mn–Ga case. Moreover, the results indicate that the termination of Mn–Ga with the lowest surface energy is the most stable termination for the application in spintronics. The optical coefficients such as real and imaginary dielectric function, refraction, extinction, energy loss function, optical conductivity and reflections of the bulk and Mn–Ga termination have been calculated and compared.

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 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.

Density functional theory of two-dimensional electron–hole complexes

2019 ◽  
Vol 33 (12) ◽  
pp. 1950152
Author(s):  
Alexander A. Vasilchenko
Keyword(s):  
Magnetic Field ◽  
Density Functional Theory ◽  
Density Functional ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Electron Hole ◽  
Functional Theory ◽  
Exchange Correlation ◽  
The Density Functional Theory ◽  
Number Of Particles

The energy of the two-dimensional electron–hole complex has been calculated in the framework of the density functional theory. We show that the energy of a direct two-dimensional exciton, without taking into consideration the exchange–correlation interaction, is very different from the exact value. We find that the number of particles in the indirect electron–hole complexes decreases with increasing interlayer distance in a strong magnetic field.

The Magnetic States of Co- and Cr-Doped Ni-Mn-(In, Sn) Heusler Alloys

2016 ◽  
Vol 97 ◽  
pp. 119-123
Author(s):  
Vasiliy D. Buchelnikov ◽  
Vladimir V. Sokolovskiy ◽  
Mikhail A. Zagrebin ◽  
Peter Entel
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Heusler Alloys ◽  
Energy Relaxation ◽  
Functional Theory ◽  
Spin Configuration ◽  
The Density Functional Theory ◽  
Magnetic States

In this paper we report on the equilibrium magnetic and structural reference states of complex Cr doped Ni-Co-Mn-(In, Sn) Heusler alloys, which are studied from first-principles within the density functional theory. The off-stoichiometric compositions were treated by using the supercell approach. Three different ferrimagnetic and one ferromagnetic spin configurations were considered. The results of energy relaxation calculations have been averaged over different atomic distributions. It is found that Ni14Co2Mn11Cr1(In, Sn)4 the ferromagnetic (a ferrimagnetic) spin configuration in austenite (martensite) is energetically stable, respectively.

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