Electronic and magnetic properties of BaUO3 by modified Becke–Johnson (mBJ) functional

2018 ◽  
Vol 32 (15) ◽  
pp. 1850164
Author(s):  
Ghulam Mustafa ◽  
Najm ul Aarifeen ◽  
Ahmad Afaq ◽  
Muhammad Asif

First-principle calculations have been performed to study the structural, electronic and magnetic properties of BaUO3 in cubic perovskite. The lattice parameter, bulk modulus, bond length, band structures, density of states, and magnetic moments are evaluated using Full Potential Linearized Augmented Plane Wave (FP-LAPW) method in Wien2k-code with GGA as exchange and correlation functional and mBJ functional is used to improve the results along with GGA+U to review magnetic properties. It is found that our calculated structural parameters are in good agreement with experimental results and other work at ambient pressure. The density of states results for spin up and spin down channels show that BaUO3 is an half ferromagnetic material, so we may use this material to make high-performance spintronics devices.

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.


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.


2018 ◽  
Vol 35 (4) ◽  
pp. 846-856 ◽  
Author(s):  
Shibghatullah Muhammady ◽  
Inge M. Sutjahja

Abstract We report structural, electronic, and magnetic properties of SrCoO3 in Pm3̅m and P4/mbm space groups, which are calculated by using generalized gradient approximation corrected with on-site Coulomb repulsion U and exchange energies J. The cubic lattice parameter a and local magnetic moments of Co (μCo) are optimized by varying U at Co 3d site. Employing ultrasoft pseudopotential, the values of U = 8 eV and J = 0.75 eV are the best choice for Pm3̅m space group. We found the value of μCo = 2.56 μB, which is consistent with the previous results. It was also found that Co 3d, hybridized with O 2p, is the main contributor to ferromagnetic metallic properties. Besides, norm-conserving pseudopotential promotes a, which is in good agreement with experimental result. However, it is not suitable for P4/mbm space group. By using ultrasoft pseudopotential, the value of U = 3 eV (J = 0.75) is the most suitable for P4/mbm group. Ferromagnetic metallic properties, Jahn-Teller distortion, and reasonable lattice parameters have been obtained. This study shows that U has significant contribution to the calculated properties and also points out that P4/mbm space group with US-PP is suitable to describe experimental results.


2019 ◽  
Vol 33 (31) ◽  
pp. 1950389 ◽  
Author(s):  
Hafsa Arshad ◽  
M. Zafar ◽  
S. Ahmad ◽  
M. Rizwan ◽  
M. I. Khan ◽  
...  

In this study, the structural, electronic and magnetic properties of Co-based equiatomic quaternary Heusler alloys (EQHA) CoPdCrZ (Z = Si, Ge, P) are investigated by full potential linearized augmented plane wave (FP-LAPW) method. Three different configurations are employed to find out the most stable structure by structural optimization process. The alloys CoPdCrSi and CoPdCrGe are found to be stable in Type-II structure while CoPdCrP is in Type-I. The calculated electronic and magnetic properties show that CoPdCrSi and CoPdCrGe are nearly half metals while CoPdCrP is a ferromagnetic alloy. By following the Slater–Pauling rule [Formula: see text], the total magnetic moments are calculated. The spin polarization and Curie temperature have also been calculated.


2021 ◽  
Vol 31 (6) ◽  
pp. 335-340
Author(s):  
Ahmed Memdouh Younsi ◽  
Lakhdar Gacem ◽  
Mohamed Toufik Soltani

Trioxides of rubidium, strontium, and ruthenium belong to the family of alkali and alkaline earth ruthenates. SrRuO3 crystallizes in various symmetry classes—orthorhombic, tetragonal, or cubic—whereas RbRuO3 is perovskite (cubic) structured and crystallizes only in the cubic space group Pm3¯¯¯m(No. 221). In this study, we investigated the structural stability as well as the electronic and magnetic properties of two cubic perovskites SrRuO3 and RbRuO3. We established the corresponding lattice parameters, magnetic moments, density of states (DOS), and band structures using ab‑initio density‑functional theory (DFT). Both compounds exhibited a metallic ferromagnetic ground state with lattice parameter values between 3.83 and 3.96 Å; RbRuO3 had magnetic moments between 0.29 and 0.34 µBwhereas SrRuO3 had magnetic moments between 1.33 and 1.66 µB. This study paves way for further RbRuO3 research.


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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Farzad Moradiannejad ◽  
S. Javad Hashemifar ◽  
Hadi Akbarzadeh

The structural, electronic, and magnetic properties of MnAs crystal are studied. The WIEN2k code which uses a full-potential LAPW program based on density functional theory with GGA is used for the calculations. At first, the total energy of a MnAs crystal in different lattices is calculated and the corresponding - diagram is drawn for two different structures of MnAs. The effect of pressuring this crystal is determined. The calculations confirm that, MnAs has the NiAs-type structure at ambient pressure but transforms into the zinc-blend structure of a specific pressure value. Also, the electric field gradient (EFG) and hyperfine field (HFF) at the nuclear site of Mn and As are calculated. Finally, the effect of pressure on EFG and HFF is studied.


2014 ◽  
Vol 28 (13) ◽  
pp. 1450103 ◽  
Author(s):  
Zobeideh Momeni Larimi ◽  
Ahmad Amirabadizadeh ◽  
Ahmad Yazdani ◽  
Hadi Arabi

The electronic structure and magnetic properties of the Gd 5 Si 4 compound have been investigated by the first principles full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT) using the WIEN2k code. The Coulomb corrected local-spin density approximation (LSDA + U) in the self-interaction correction (SIC) has been used for the exchange-correlation potential. Based on the calculated results, the ground state of Gd 5 Si 4 is found to be ferromagnetic (FM). The optimized structural parameters and magnetic properties including the lattice constants and magnetic moments are in good agreement with experimental data. The magnetic moments of the Gd atoms in Gd 5 Si 4 are smaller than that of the elemental gadolinium. The magnetic moment of Gd 5 Si 4 is found to be 37.8 μB/f.u. DOS results show that the magnetic properties of the compound depend on the hybridization between Si -3p and Gd -5d states which have an effective role in the RKKY interaction. The existence of the very flat bands at -7 eV for spin up and at +3 eV for spin down that is mainly Gd -4f characters shows that the LSDA + U method provides the better description of our systems. The obvious overlap of electron densities between the Gd1 and Si atoms indicates a covalent-like bonding between them.


SPIN ◽  
2017 ◽  
Vol 07 (04) ◽  
pp. 1750010 ◽  
Author(s):  
L. Seddik ◽  
S. Amari ◽  
K. O. Obodo ◽  
L. Beldi ◽  
H. I. Faraoun ◽  
...  

In this study, we present the calculated structural, electronic and magnetic properties of mixed Heusler alloys (Ni[Formula: see text]Co[Formula: see text]MnSn. Using ab initio calculations with the full-potential augmented plane-wave method (FP-LAPW), we evaluated the various possible configurations of Ni and Co sites in the (Ni[Formula: see text]Co[Formula: see text]MnSn crystallographic lattice. The lowest energy configuration is determined based on energetic considerations. The calculated equilibrium lattice parameters and magnetic moments are in a reasonable agreement with available experimental data. Of interest, we found that the change of total magnetic moment can be interpreted as a linear variation of the magnetic moment of manganese and cobalt atoms.


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>


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