scholarly journals First-principles study of structural, electronic and magnetic properties of Co-based quaternary Heusler compounds: CoFeCrAl, CoFeTiAs, CoFeCrGa and CoMnVAs

BIBECHANA ◽  
2017 ◽  
Vol 15 ◽  
pp. 50-59 ◽  
Author(s):  
Bikram Pandey ◽  
Ram Babu Ray ◽  
Gopi Chandra Kaphle

We study the Structural, Electronic and Magnetic properties of Co-based LiMgPdSn-types of quaternary Heusler compounds (CoFeCrAl, CoFeTiAs, CoFeCrGa, and CoMnVAS) using Density Functional Theory (DFT) implemented on Tight Binding Linear Muffin-Tin Orbital within Atomic Sphere Approximation(TB-LMTO-ASA) Code. The optimized value of lattice parameter for CoFeCrAl, CoFeTiAs, CoFeCrGa and CoMnVAs are found to be 5.61A˚, 5.76 A˚, 5.61A˚ and 5.71A˚ respectively. From the calculation of electronic band structure and spin polarized total density of states (DOS), we found that CoFeCrAl and CoFeCrGa are spin-gapless semiconductor with half-metallic gap of 0.82eV and 0.25eV respectively. CoFeTiAs half-metals (Nearly spin-gapless semiconductor) with half-metallic gap 0.38 eV and CoMnVAs is found to be nearly gapless half-metal. Magnetic moment of these compounds almost obey the Slater-Pauling rules. All these compounds  expected to have high curie temperature which makes them significant for spintroincs/magnetoelectroincs applications.BIBECHANA 15 (2018) 50-59 

2017 ◽  
pp. 31-36
Author(s):  
Prakash Sharma ◽  
Gopi Chandra Kaphle

Heusler alloys have been of great interest because of their application in the field of modern technological word. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co2MnSi have been studied using Density functional theory based Tight Binding Linear Muffin Tin Orbital with Atomic Sphere Approximation (TB-LMTO-ASA) approach. From the calculation lattice parameter of optimized structure of Co, Mn, Si and Co2MnSi are found to be 2.52A0 , 3.49A0 , 5.50A0 , 5.53A0 respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co2MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co2MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co2MnSi are magnetic with magnetic moment 2.85μB and 4.91μB respectively. The contribution of orbitals in band, DOS and magnetic moment are due to d-orbitals of Co and Mn and little from s and p-orbital of Si in Co2MnSi.The Himalayan Physics Vol. 6 & 7, April 2017 (31-36)


2017 ◽  
Vol 4 (1) ◽  
pp. 60
Author(s):  
Prakash Sharma ◽  
Gopi Chandra Kaphle

<p class="Default">Heusler alloys have been of great interest because of their application in the field of modern technological applications. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co<sub>2</sub>MnSi have been studied using Density functional theory based Tight Binding Linear Muffin Tin Orbital with Atomic Sphere Approximation (TB-LMTO-ASA) approach. From the calculation lattice parameter of optimized structure of Co, Mn, Si and Co<sub>2</sub>MnSi are found to be 2.52Å, 3.49Å, 5.50Å, 5.53Å respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co<sub>2</sub>MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co<sub>2</sub>MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co2MnSi are magnetic with magnetic moments 2.85μ<sub>B</sub> and 4.91μ<sub>B</sub> respectively. The contribution of orbital in band structure, DOS and magnetic moments are due to d-orbital of Co and Mn and little from s and p-orbital of Si in Co<sub>2</sub>MnSi alloy.</p><p><strong>Journal of Nepal Physical Society</strong><em><br /></em>Volume 4, Issue 1, February 2017, Page: 60-66</p>


2014 ◽  
Vol 70 (a1) ◽  
pp. C1806-C1806
Author(s):  
Samir Bentata ◽  
Bouabdellah Bouadjemi ◽  
Tayeb Lantri ◽  
Wissem Benstaali

We investigate the structural, electronic and magnetic properties of the orthorhombic Perovskite oxyde NdMnO3 through density-functional-theory (DFT) calculations using both generalized gradient approximation GGA+U, where U is on-site Coulomb interaction correction. The electronic band structure, the partial and total density of states (DOS) and the magnetic moment are determined. The results show a half-metallic ferromagnetic ground state for the orthorhombic NdMnO3.


2016 ◽  
Vol 61 (1) ◽  
pp. 369-374 ◽  
Author(s):  
K. Gruszka ◽  
M. Nabiałek ◽  
T. Noga

Paper presents results of studies on structural, electronic and magnetic properties of YFe5 compound using density functional theory (DFT) approach. The GGA functional with ultrasoft pseudopotentials were used as implemented in Quantum Espresso software. The structure of YFe5 compound was examined in three different states namely nonmagnetic, antiferromagnetic and ferromagnetic. Also two antiferromagnetic configurations were considered. From the total energy viewpoint the most likely ferromagnetic configuration is favorable. In order to achieve mentioned aims we present projected density of states, electronic band structure and Löwdin population analysis studies results.


2019 ◽  
Vol 5 (1) ◽  
pp. 42-53
Author(s):  
D. Parajuli ◽  
G. C. Kaphle ◽  
K. Samatha

The electronic and magnetic properties of Titanium and one of its oxide Anatase are calculated by using Tight Binding Linear Muffin-Tin Orbital Atomic Sphere Approximation (TB-LMTO-ASA) method under Density Functional Theory (DFT). The lattice parameter, band structure, Density of States (DOS) and charge density distributions of Ti and TiO2 (Anatase) required for electronic structure are calculated respectively. The orbital contribution is analyzed by fat band structure; the d- orbital on conduction band and, s and p orbitals on valance bands. Consequently, their magnetic properties are checked. From our study, we found that the magnetic moments of Ti and TiO2 are found to be 2.2 μB and 0 respectively. The total Density of States for spin up and down electron have smaller difference in Ti and symmetric in TiO2 indicates that Ti slightly paramagnetic and Anatase is non magnetic in nature. The charge density plots reveals the concentration of electrons at the site under study. Anatase can be deposited onto Mxene to form Mxene-Anatase nanocomposite which has several excellent applications in the field of biosensors, biocompatible materials, energy storage devices, topological insulators etc.


2016 ◽  
Vol 34 (4) ◽  
pp. 905-915 ◽  
Author(s):  
M. Rahmoune ◽  
A. Chahed ◽  
A. Amar ◽  
H. Rozale ◽  
A. Lakdja ◽  
...  

AbstractIn this work, first-principles calculations of the structural, electronic and magnetic properties of Heusler alloys CoMnYAl, CoMnYGa and CoMnYIn are presented. The full potential linearized augmented plane waves (FP-LAPW) method based on the density functional theory (DFT) has been applied. The structural results showed that CoMnYZ (Z = Al, Ga, In) compounds in the stable structure of type 1+FM were true half-metallic (HM) ferromagnets. The minority (half-metallic) band gaps were found to be 0.51 (0.158), 0.59 (0.294), and 0.54 (0.195) eV for Z = Al, Ga, and In, respectively. The characteristics of energy bands and origin of minority band gaps were also studied. In addition, the effect of volumetric and tetragonal strain on HM character was studied. We also investigated the structural, electronic and magnetic properties of the doped Heusler alloys CoMnYGa1−xAlx, CoMnYAl1−xInx and CoMnYGa1−xInx (x = 0, 0.25, 0.5, 0.75, 1). The composition dependence of the lattice parameters obeys Vegard’s law. All alloy compositions exhibit HM ferromagnetic behavior with a high Curie temperature (TC).


2021 ◽  
Author(s):  
O. T. Uto ◽  
J. O. Akinlami ◽  
S. Kenmoe ◽  
G. A. Adebayo

Abstract The CoYSb (Y = Cr, Mo and W) compounds which are XYZ type half-Heusler alloys and also exist in the face centred cubic MgAgAs-type struc-ture conform to F ̄43m space group. In the present work, these compoundsare investigated in different atomic arrangements called, Type-I, Type-II andType-III phases, using Generalized Gradient Approximation (GGA) in the Density Functional Theory (DFT) implemented in QE (Quantum EspressoAb-Initio Simulation Package). The ferromagnetic state of these alloys is studied after investigating their stable structural phase. The calculated electronic band structure and the total electronic density of states indicated nearly half-metallic behaviour in CoMoSb with a possibility of being used in spintronic application, metallic in CoWSb and half-metallic in CoCrSb, with the minority spin band gap of 0.81 eV. Furthermore, the calculated mechanical properties predicted an anisotropic behaviour of these alloys in the stable phase. Finally, due to its high Debye temperature value, CoCrSb possesses a stronger covalent bond than CoMoSb and CoWSb, respectively.


SPIN ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 2050022 ◽  
Author(s):  
K. Belkacem ◽  
Y. Zaoui ◽  
S. Amari ◽  
L. Beldi ◽  
B. Bouhafs

The first-principles approach based on density functional theory (DFT) and the full-potential linearized augmented plane-wave method were employed to investigate the structural, elastic, electronic and magnetic properties of Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys. The generalized gradient approximation (GGA) as parameterized by Perdew, Burke and Ernzerhof (PBE) and the modified Becke–Johnson exchange potential were used. As far as we know, we present our results which for the first time quantitatively account for the electronic structures and magnetic properties of Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys. From the total energy calculation using three possible atomic configurations ([Formula: see text], [Formula: see text] and [Formula: see text]), it is found that the Na[Formula: see text]NO ([Formula: see text], Sr and Ba) quaternary half-Heusler alloys are more stable in the ferromagnetic [Formula: see text]-phase. From our estimated elastic constants [Formula: see text], it is found that all the considered Heusler alloys are mechanically stable in the [Formula: see text]-phase. We have also investigated the robustness of the half-metallicity with respect to the variation of lattice constants in these alloys. We have found that these alloys are half-metallic ferromagnets (HMFs) with a magnetic moment of 2[Formula: see text][Formula: see text] per formula unit at their equilibrium volumes. The spin-polarized electronic band structure and density of states of these quaternary half-Heusler alloys calculated by GGA (mBJ-GGA) show that the minority spin channels have metallic nature and the majority spin channels have a semiconductor character with half-metallic gaps of 0.49[Formula: see text]eV (2.17[Formula: see text]eV), 0.72[Formula: see text]eV (2.28[Formula: see text]eV) and 0.96[Formula: see text]eV (2.22[Formula: see text]eV) for NaCaNO, NaSrNO and NaBaNO quaternary half-Heusler alloys, respectively. Analysis of the density of states and the spin charge density of these quaternary alloys indicates that their magnetic moments mainly originate from the strong spin-polarization of 2[Formula: see text] states of N atoms and O atoms.


2017 ◽  
Vol 95 (11) ◽  
pp. 1031-1036
Author(s):  
D. Vijayalakshmi ◽  
G. Kalpana

Structural, electronic, and magnetic properties of ternary CdMAs2 (M = Sc, Ti, and V) compounds in the chalcopyrite structure have been studied using full-potential linearized augmented plane wave method based on density functional theory. We present a detailed study of electronic band structure, density of states, and magnetic moment of all three compounds within local spin density approximation and generalized gradient approximation. CdMAs2 compounds are derived from chalcopyrite structured CdGeAs2 with the substitution of transition metal (TM) atoms at Ge site. Negative values of formation energy signify that these materials are stable in chalcopyrite structure. Spin-polarized calculations show that the substitution of TM atoms at the group IV site influences the appearance of ferromagnetic state (FM) in CdScAs2 and CdVAs2 compounds. FM in CdScAs2 and CdVAs2 compounds is mainly due to the strong spin polarization of 3d states of M cations and 4p states of As anion. CdVAs2 also exhibits half metallic ferromagnetism with an integer magnetic moment of 1.00μB per formula unit. However, there is no effective spin-polarization of energy states at the Fermi level in CdTiAs2 compound and shows a non-magnetic behaviour.


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