scholarly journals Spinelectronic investigation of the quaternary vanadium fluoride Rb2NaVF6: Ab-initio method

2020 ◽  
Vol 66 (5 Sept-Oct) ◽  
pp. 604
Author(s):  
M. Berber ◽  
N. Bouzouira ◽  
H. Abid ◽  
A. Boudali ◽  
H. Moujri
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Exchange Correlation ◽  
Spin Polarized ◽  
Higher Temperature ◽  
Good Agreement

In this study, we have investigated the structural, electronic, and magnetic properties of the Rb2NaVF6 compound. We have performed our calculations by the use of first-principle methods based on spin-polarized density functional theory, where the electronic exchange-correlation potential is treated by the generalized gradient approximation GGA- PBEsol coupled with the improved TB-mBJ approach. The calculated structural parameters of Rb2NaVF6 are in good agreement with the available experimental data. Rb2NaVF6 exhibits a half-metallic ferromagnetic feature with a spin polarization of 100 % at the Fermi level and a direct large half-metallic gap of 3.582 eV. The total magnetic moments are 2 μB. This material is half-metallic ferromagnets, and it can be potential candidates for spintronics applications at a higher temperature.

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.

POSSIBLE Si-BASED HALF-METALLIC MATERIALS: MnSi46 CLATHRATES

2012 ◽  
Vol 26 (18) ◽  
pp. 1250114
Author(s):  
ZHI-WEI ZHAO ◽  
JING WANG ◽  
HUI-YAN ZHAO ◽  
YING LIU
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Density Functional Theory Calculations ◽  
Metallic Materials ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Silicon Clathrates ◽  
Ni Dopant ◽  
Center Site

The structural and magnetic properties of M Si 46 (M = Mn , Fe , Co and Ni ) clathrates have been studied using density functional theory calculations within the generalized gradient approximation. When the structures involve a dopant at the center of a Si 20 or Si 24 cage, the results show that the neighboring atoms around the dopant are drawn in toward the center. Some of the silicon clathrates with a Mn or Co dopant at the center site of a Si 20 cage, or a Mn , Fe or Ni dopant at the center site of a Si 24 cage are found to be half-metallic materials with large magnetic moments, and others with a Fe or Ni dopant at the center site of a Si 20 cage or a Co dopant at the center site of a Si 24 cage display semi-metallic characters. In particular, MnSi 46 with a half-metallic gap of 0.70 eV and a magnetic moment of 5.00 μ B shows promise for applications in the field of spintronics.

MAGNETIC MAP OF MnNi ALLOYED MONOLAYER ON Cu(001) SUBSTRATE: AB-INITIO CALCULATIONS

2010 ◽  
Vol 09 (06) ◽  
pp. 619-622
Author(s):  
BOTHINA A. HAMAD
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Exchange Correlation Potential ◽  
The Density Functional Theory ◽  
Correlation Potential

In this work, a theoretical study of the structural, electronic and magnetic properties are presented for Mn 0.5 Ni 0.5 alloyed overlayer adsorbed on Cu (001) surface. The calculations were performed using the density functional theory (DFT) and the exchange-correlation potential was treated by the generalized gradient approximation (GGA). The system was fully relaxed except for the central layer, which yields to outward relaxations and inward Mn and Ni surface atoms, respectively in the ferromagnetic and antiferromagnetic configurations. The in-plane ferromagnetic configuration was found to be more stable than the antiferromagnetic one by 25 meV/atom. The local magnetic moments of Mn atoms were found to be about 4 μ B , whereas those of the Ni atoms where found to be 0.46 μ B .

scholarly journals Structural and piezoelectric coefficients of AlP under pressure

2018 ◽  
Vol 6 (2) ◽  
pp. 53
Author(s):  
Salah Daoud ◽  
Rabie Mezouar ◽  
Abdelfateh Benmakhlouf
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Generalized Gradient ◽  
Aluminum Phosphide ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Zinc Blende ◽  
Density Functional Perturbation Theory ◽  
The Density Functional Theory

The present work aims to investigate the structural parameters and the piezoelectric coefficients of cubic zinc-blende Aluminum phosphide (AlP) under high pressure up to 21 GPa, using plane wave-pseudopotential (PW-PP) approach in the framework of the density functional theory (DFT) and the density functional perturbation theory (DFPT) with the generalized gradient approximation (GGA) for the exchange-correlation functional. The results obtained are analyzed and compared with other data of the literature. The structural parameters and the piezoelectric coefficients calculated here agree well with other data of the literature. We found also that both the direct and converse piezoelectric coefficients increase with increasing pressure up to 21 GPa. 

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.

A Density Functional Theory Study of Gd8O12 Cluster

2012 ◽  
Vol 542-543 ◽  
pp. 1418-1421
Author(s):  
Qing Xiang Gao ◽  
Lin Xu ◽  
Bo Wu
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Cage Structure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Spin Polarized ◽  
Ionic Bonds

The spin-polarized generalized gradient approximation to the density functional theory is used to determine the geometries, stability, electronic structures, and magnetic properties of the Gd8O12cluster. Our work reveals that the ground state configuration of the Gd8O12cluster is a hexahedral cage structure with Cisymmetry. The electronic and magnetic properties imply that the formations of the ionic bonds between the adjacent Gd and O atoms result in the high stability of the Gd8O12cluster, which is due to the charge transfers between the Gd 5d, 6s electrons to O 2p orbital. It is also confirmed by the electron densities of HOMO-LUMO states. In addition, the analysis of the magnetic properties implies the total magnetic moments are mostly dominated by the Gd 4f orbital.

Electronic, Optical and Vibrational Properties of B3N3H6 from First-Principles Calculations

2021 ◽  
Author(s):  
Yun-Dan Gan ◽  
Han Qin ◽  
Fu-Sheng Liu ◽  
Zheng-Tang Liu ◽  
Cheng lu Jiang ◽  
...  
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Conductivity Loss ◽  
Good Agreement

Abstract The electronic, optical and vibrational properties of B3N3H6 have been calculated by means of first-principles density functional theory (DFT) calculations within the generalized gradient approximation (GGA) and the local density approximation (LDA). The calculated structural parameters of B3N3H6 are in good agreement with experimental work. With the band structure and density of states (DOS), we have analyzed the optical properties including the complex dielectric function, refractive index, absorption, conductivity, loss function and reflectivity. By the contrast, it is found that on the (001) component and (100) component have obvious optical anisotropy. Moreover, the vibrational properties have been obtained and analyzed.

Induced Magnetism in Non-metal Doped CdS Monolayer

2021 ◽  
Vol 9 (2) ◽  
pp. 91-99
Author(s):  
Lalmuan chhana ◽  
◽  
Ramesh Chandra Tiwari ◽  
Lalhriat zuala ◽  
Dibya Prakash Rai ◽  
...  
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Density Functional Theory Calculations ◽  
Local Magnetic Moment ◽  
Valence Band Maximum ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
C And N ◽  
Metal Doped

The structural, electronic, and magnetic properties of CdS monolayer doped with non-metallic (NM) atoms B, C and N are studied based on ab initio density functional theory calculations within the generalized gradient approximation as revised for solids by Perdew, Burke and Ernzerhof (PBE-sol). The total magnetic moments per supercell of B, C and N-doped CdS monolayer is found to be ~1.0 µB, ~2.0 µB and ~1.0 µB respectively. As the electronegativity of the dopant increases, the local magnetic moment tends to localize and 2p-states of the dopants gradually move towards the valence band maximum of the host CdS. Our study also confirmed that the introduction of impurity atom by substitution of S atom results in half-metallic magnetism. Our investigation concludes that doping of NM element is an efficient way of altering the magnetic and electronic properties in CdS monolayer.

Ferromagnetism in RaBi with Zinc-Blende and Wurtzite Structures: Ab-initio Prediction

SPIN ◽  
2018 ◽  
Vol 08 (02) ◽  
pp. 1850008 ◽  
Author(s):  
H. Benaissa ◽  
S. Benatmane ◽  
S. Amari ◽  
K. O. Obodo ◽  
L. Beldi ◽  
...  
Keyword(s):  
Density Functional ◽  
Magnetic Behavior ◽  
Binary Compound ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Spintronic Devices ◽  
Zinc Blende ◽  
Ab Initio Prediction ◽  
Spin Polarized

Using density-functional theory within the generalized-gradient approximation, we explore the magnetic behavior induced by nonmagnetic atoms Ra and Bi in RaBi binary compound in five crystalline structures (rocksalt (B1), CsCl (B2), ZB (B3), WZ (B4) and NiAs (B8[Formula: see text]. In all the structures considered, the ferromagnetic (FM) phase is energetically less favorable compared to the paramagnetic phase except in the ZB and WZ structures. In the (FM) ZB and WZ structures, we obtained that the spin polarized 6[Formula: see text] orbitals of bismuth in the RaBi compound results in a half-metallic (HM-FM) ferromagnet with an integer magnetic moment of 1[Formula: see text][Formula: see text] per formula unit. We calculated spin flip gaps (half-metallic gaps) of 0.16 and 0.18[Formula: see text]eV within GGA-PBE approach, 0.40[Formula: see text]eV and 0.33[Formula: see text]eV with mBJ-GGA-PBE approach for ZB and WZ structures, respectively. The RaBi compound in ZB and WZ structures would have potential application in spintronic devices.

First-Principles Investigation of Electronic Structural and Optical Properties of Rare Earth Doped β-Si3N4 Crystals

2012 ◽  
Vol 512-515 ◽  
pp. 864-868 ◽  
Author(s):  
Dong Qiu ◽  
Xue Feng Lu ◽  
Bai Hai Li ◽  
Hong Jie Wang
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Density Functional ◽  
Structural Parameters ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Good Agreement

Based on the density functional theory within the generalized gradient approximation (GGA) method, the geometric structure, electronic and dielectric properties of rare earth (La and Y) doped β-Si3N4 were studied and the origin of the differences and similarities among the rare earths (La and Y) characterized in this work were discussed. The fully relaxed structural parameters of β-SiN4 crystal are found to be in good agreement with experimental data. The formation energy calculations indicate that both La and Y atoms are preferentially doped on the Si sites, which is in agreement with previous experimental observations. Furthermore, the calculated band gap of the doped structures decreases significantly, specifically, the larger La atom results in narrower band gap than that of Y doped β-Si3N4. The reason was extensively analyzed by the density of states (DOS). Subsequently, the dielectric function, absorption coefficient of the polycrystalline were compared with these values for plane polarized at [100] and [001] directions. The calculations show that the optical dielectric constant in the rare earth (especially La) doped structures increase remarkably, compared with the undoped β-Si4N4.

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