Structural, Electronic and Magnetic Properties of CaSe Doped with 3d (V, Cr and Mn)

SPIN ◽  
2021 ◽  
Author(s):  
Youcef Daoudi ◽  
Hadj Moulay Ahmed Mazouz ◽  
Brahim Lagoun ◽  
Ali Benghia

We report first-principles investigation on structural, electronic and magnetic properties of 3d transition metal element-doped rock-salt calcium selenide Ca[Formula: see text]TMxSe (TM = V, Cr and Mn) at concentrations [Formula: see text] = 0.0625, 0.125 and 0.25. We performed the calculations in the framework of the density functional theory (DFT) using the full-potential linearized augmented plane waves plus local orbitals (FP-LAPW+lo) method within the Wu–Cohen generalized gradient approximation (WC-GGA) for the structural optimization and the Tran–Blaha modified Becke–Johnson (TBmBJ) potential for the electronic and the magnetic properties. The computed spin-polarized band structures and densities of states show that Ca[Formula: see text]CrxSe compounds at all studied concentrations are half-metallic ferromagnets with a complete spin polarization of 100% at Fermi-level while the Ca[Formula: see text]VxSe and Ca[Formula: see text]MnxSe are ferromagnetic semiconductors. The total magnetic moments for Ca[Formula: see text]VxSe, Ca[Formula: see text]CrxSe, and Ca[Formula: see text]MnxSe show the integer values of 3[Formula: see text][Formula: see text], 4[Formula: see text][Formula: see text], and 5[Formula: see text][Formula: see text], respectively, with a major contribution of transition metal elements (TM) in the total magnetization. Also, we reported the calculated exchange constants [Formula: see text] and [Formula: see text] and the band edge spin splitting of the valence ([Formula: see text]) and conduction ([Formula: see text]) bands. The ferromagnetism of these compounds is due to the super-exchange and the double-exchange mechanisms in addition to the strong p–d exchange interaction. Therefore, the predicted results indicate that the diluted Ca[Formula: see text]TMxSe (TM = V, Cr, Mn) compounds are suitable candidates for a possible application in the field of spintronic technology.

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050013 ◽  
Author(s):  
Amina Aiche ◽  
Abdelkader Tadjer ◽  
Hadj Moulay Ahmed Mazouz ◽  
Bendouma Doumi ◽  
Houari Khachai

The electronic structure and magnetic properties of diluted Ca[Formula: see text]TMxS (TM[Formula: see text][Formula: see text][Formula: see text]V, Cr and Co) in the rocksalt structure at concentrations [Formula: see text], 0.125 and 0.25 were studied using the full-potential linearized augmented plane wave approximation of the density functional theory with the Wu-Cohen generalized gradient approximation (WC-GGA) and the Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential. Features such as lattice constant, bulk modulus, spin-polarized band structures, total and local densities of states and magnetic properties have been computed. The electronic structure show that Ca[Formula: see text](V, Cr)xS at all the studied concentrations and the diluted Ca[Formula: see text]CoxS with [Formula: see text] compounds are half-metallic ferromagnets with spin polarization of 100%. The calculated total magnetic moments for Ca[Formula: see text]VxS and Ca[Formula: see text]CoxS show the same integer value of 3[Formula: see text][Formula: see text] per formula unit and Ca[Formula: see text]CrxS exhibit a total magnetic moment of 4[Formula: see text][Formula: see text], which confirm the half-metallic behavior of these compounds. We also calculated the values of the band edge spin splitting of the valence and conduction bands and the exchange constants. We have found that the ferromagnetic state is stable by the p-d exchange associated with the double-exchange mechanism. The diluted Ca[Formula: see text](V,Cr,Co)xS are found to be new promising candidates for spintronic applications.


2018 ◽  
Vol 32 (16) ◽  
pp. 1850201
Author(s):  
Israr Ullah ◽  
Shahid Mehmood ◽  
Zahid Ali ◽  
Gul Rehman ◽  
Imad Khan ◽  
...  

In this paper, structural, electronic and magnetic properties of the aluminum-rich intermetallic alloy Al[Formula: see text]Fe4 are investigated using full potential linearized augmented plane waves (FPLAPW) approach in the frame work of density functional theory (DFT). The calculated structural parameters are consistent with the experimentally reported data. In this alloy, Fe atoms possess different coordination numbers with Al atoms, i.e., Fe(1) and Fe(2) have the same coordination number 5, whereas Fe(3), Fe(4) and Fe(5) have 4, 7 and 9 coordination numbers, respectively. The compound is found metallic and ferromagnetic in nature. Post-DFT (BoltzTraP code) calculations confirm the ferromagnetic and anisotropic behavior. The Fe(5) atom plays a central role in the electronic and magnetic properties of the alloy due to the large coordination with Al atom as compared to the rest Fe atoms.


2020 ◽  
Vol 98 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Shabbir Ahmed ◽  
M. Shakil ◽  
Muhammad Zafar ◽  
M.A. Choudhary ◽  
T. Iqbal

We have studied the structural, electronic, and magnetic properties of CrMnX (X = Ge, Se, Si, and Sn) compounds. The first principles band structure calculation within the framework of density functional theory was used to explore these properties. The full-potential linearized augmented plane wave (FP-LAPW) method as implemented in the Wien2k software package has been used. We investigated the effect of compositional variation on lattice constants, bulk modulus, electronic, and magnetic properties. CrMnSi has the largest while CrMnSe has the smallest bulk modulus among the studied compounds. Our calculated electronic and magnetic properties for CrMnX (X = Ge, Se, Si, and Sn) compounds show that CrMnGe, CrMnSe, and CrMnSi are half-metallic materials with integer magnetic moments while CrMnSn has metallic behavior. These compounds are fascinating for spintronic devices due to their half-metallic properties.


2018 ◽  
Vol 64 (2) ◽  
pp. 135 ◽  
Author(s):  
Boucif Benichou ◽  
Zakia Nabi ◽  
Badra Bouabdallah ◽  
Halima Bouchenafa

We investigate the structural, elastic, electronic and magnetic properties of the Heusler compounds Cu2MnSi, Cu2MnAl and Cu2MnSi1-xAlx quaternary alloys, using the full-potential linear-augmented plane-wave method (FP-LAPW) in the framework of the density functional theory (DFT) using the generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA-PBE). Our results provide predictions for the quaternary alloy Cu2MnSi1-xAlx            (x = 0.125, 0.25, 0.375, 0.5) in which no experimental or theoretical data are currently available. We calculate the ground state’s properties of Cu2MnSi1-xAlx alloys for both nonmagnetic and ferromagnetic configurations, which lead to ferromagnetic and metallic compounds. Also, the calculations of the elastic constants and the elastic moduli parameters show that these quaternary Heusler alloys are ductile and anisotropic.


2017 ◽  
Vol 35 (2) ◽  
pp. 283-290
Author(s):  
B. Arghavani Nia ◽  
R. Moradian ◽  
M. Shahrokhi

Abstract Structural, electronic and magnetic properties of transition metal TM (TM = Fe, Co and Ni) atomic chains wrapped in single walled LiF armchair nanotubes have been investigated by the first-principles calculations in the framework of the density functional theory. The generalized gradient approximation (GGA) with Hubbard repulsion potential and without Hubbard repulsion was employed to describe the exchange-correlation potential. It is found that all these TM chains @LiFNTs systems have negative formation energy so they are stable and exothermic. Total density of states and partial densities of states analyses show that the spin polarization and the magnetic moment of TM chains @LiFNTs(n,n) systems come mostly from the TM atom chains. All these nanocomposites are ferromagnetic (FM) and spin splitting between spin up and down is observed. The high magnetic moment and spin polarization of the TM chains @LiFNT(n,n) systems show that they can be used as magnetic nanostructures possessing potential current and future applications in permanent magnetism, magnetic recording, and spintronics.


2020 ◽  
Vol 62 (1) ◽  
pp. 71-94
Author(s):  
Filalli Sihem ◽  
Hamdad Noura

AbstractThe structural, electronic and magnetic properties of (Cubic Pm-3m, Hexagonal-4H, orthorhombic Pnma, and orthorhombic Pbnm) phases of AFeF3 Fluorides (A = Cs, Na, and Rb) are reported theoretically using full potential linearized augmented plane waves method within the density functional theory (DFT). Using different exchange–correlation approximations including the generalized gradient approximation (PBE-GGA, WC-GGA, and PBEsol-GGA), also (GGA) with Hubbard potential (GGA + U) and The modified Becke Johnson potential (mBJ), we carried to determine various physical properties. The Calculations revealing that the estimated structural parameters are reliable with the experimentally reported data. Magnetically all these intermetallics are Ferromagnetic (FM). The ground-state energy of different magnetic phases studied showed that the magnetic moments are evaluated per atom, and overestimated by (GGA+U). Transfer charge reveals a strong covalent interaction between Fe-Fe atoms. Their electronic band structure and density of states indicate insulator behavior.


2016 ◽  
Vol 3 (1) ◽  
pp. 50 ◽  
Author(s):  
Madhav Prasad Ghimire ◽  
Gopi Chandra Kaphle ◽  
R.K. Thapa

<p>We have studied the electronic and magnetic properties of double perovskites Nd<sub>2</sub>MgIrO<sub>6</sub> by means of full-potential linearized augmented plane wave (FP-LAPW) method based on density-functional theory (DFT). For the exchange-correlation potential, generalized gradient approximation (GGA) has been used. Based on our DFT calculations, Nd<sub>2</sub>MgIrO<sub>6</sub> is found to have an antiferromagnetic (AFM) ground state. The material shows Mott-Hubbard type insulator, which is observed to occur due to strong correlation in Nd-4f and Ir-5d states in addition to large crystal distortion, observed in the system. Strong hybridization between O-2p, Ir-5d and Nd-4f electrons are observed from the density of states findings. Our results shows that the 5d electrons of Ir hybridize strongly with O-2p states close to the Fermi level giving rise to the insulating state with a Mott-gap of ~0.9 eV in Nd<sub>2</sub>MgIrO<sub>6</sub>. Our study suggests that the total magnetic moment reduces to 5.0 μ<sub>B</sub> per formula unit as a result of itinerant super-exchange rather than the exchange interaction involving individual ions of Nd and Ir atoms.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 50-54</p>


2020 ◽  
Author(s):  
Amaria Bekhti-Siad ◽  
M. Baira ◽  
A. Bekhti Siad ◽  
M. E. Monir ◽  
F. Z. Dahou

Abstract The structural, elastic, electronic and magnetic properties of cubic double perovskite Pb2FeTaO6 have been investigated using self-consistent ab-initio calculation through full-potential linearized augmented plane wave (FP-LAPW) method within the frame work of the spin-polarized density functional theory (DFT), considering generalized gradient approximation (GGA) described by Perdew–Burke–Ernzerhof (PBE), GGA+U and mBJ-GGA. Pb2FeTaO6 is found as ductile material from the elastic calculations. The obtained magnetic results show that Pb2FeTaO6 is stable in the ferromagnetic state; the electronic properties show a half-metallic behavior using GGA and GGA+U and a semiconducting one with TB-mBJ, magnetic moments of each atom are also discussed in this study. These results confirm the use of this compound in spintronic devices.


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).


Author(s):  
Mohamed Helal ◽  
H. M. El-Sayed ◽  
Ahmed A Maarouf ◽  
Mohamed Fadlallah

Motivated by the successful preparation of two-dimensional transition metal dichalcogenides (2D- TMDs) nanomeshes in the last three years, we use density functional theory (DFT) to study the structural stability, mechanical,...


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