scholarly journals Half-Metallic Property Induced by Double Exchange Interaction in the Double Perovskite Bi2BB′O6 (B, B′ = 3d Transitional Metal) via First-Principles Calculations

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1844 ◽  
Author(s):  
Hong-Zong Lin ◽  
Chia-Yang Hu ◽  
Po-Han Lee ◽  
Albert Zhong-Ze Yan ◽  
Wen-Fang Wu ◽  
...  
Keyword(s):  
Exchange Interaction ◽  
Density Functional ◽  
Double Exchange ◽  
Double Perovskite ◽  
Transition Metal Ions ◽  
Spin Interaction ◽  
Metallic Materials ◽  
Generalized Gradient ◽  
Double Exchange Interaction ◽  
Half Metallic

In this paper, we identify three possible candidate series of half-metals (HM) from Bi-based double perovskites Bi2BB′O6 (BB′ = transition metal ions) through calculations utilizing the density functional theory (DFT) and full-structural optimization, in which the generalized gradient approximation (GGA) and the strong correlation effect (GGA + U) are considered. After observing the candidate materials under four types of magnetic states, i.e., ferromagnetic (FM), ferrimagnetic (FiM), antiferromagnetic (AF), and nonmagnetic (NM), we found eight promising candidates for half-metallic materials. Under the GGA scheme, there are three ferromagnetic-half-metal (FM-HM) materials, Bi2CrCoO6, Bi2CrNiO6 and Bi2FeNiO6, and three FiM-HM materials, Bi2FeZnO6, Bi2CrZnO6 and Bi2CoZnO6. With implementation of the Coulomb interaction correction (GGA + U), we find two stable half-metallic materials: Bi2CrNiO6 and Bi2CrZnO6. We determine that the stability of some of these materials are tied to the double exchange interaction, an indirect interaction within the higher powers of localized spin interaction among transition metals via oxygen ions. Found in half-metallic materials, and especially those in the ferromagnetic (FM) state, the double exchange interaction is recognized in the FM-HM materials Bi2CrCoO6 and Bi2FeNiO6.

THEORETICAL PREDICTION OF A NEW TYPE OF HALF-METALLIC MATERIALS IN DOUBLE DEROVSKITE Pb2BB′O6 (B, B′ = 3d TRANSITION METAL) VIA FIRST-PRINCIPLE CALCULATIONS

SPIN ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1450001
Author(s):  
HUEI-RU FUH ◽  
KE-CHUAN WENG ◽  
YUN-PING LIU ◽  
YIN-KUO WANG
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Interaction Mechanism ◽  
Double Exchange ◽  
Double Perovskite ◽  
Generalized Gradient ◽  
Double Exchange Interaction ◽  
Half Metallic ◽  
Metal Atoms ◽  
Transition Metal Atoms

This study investigate the electronic structure of double perovskite Pb 2BB′ O 6 (B, B′ = 3d transition metal atoms) with ab initio calculation. Density functional theory with generalized gradient approximation (GGA) is used to determine the physical proprieties of the materials. Six new half-metallic (HM) materials are found from 45 [Formula: see text] combinations in double perovskite Pb 2BB′ O 6 (of 3d transition metal atoms). There are five ferromagnetic (FM)-HM materials ( Pb 2 ScCrO 6, Pb 2 ScMnO 6, Pb 2 TiVO 6, Pb 2 TiCrO 6 and Pb 2 CrMnO 6) and one ferrimagnetic (FiM)-HM material ( Pb 2 TiFeO 6). The HM property of the materials are attributed to the double-exchange interaction mechanism through the B(t2g)- O (2p)-B′(t2g) π-binding. Besides including the on site Coulomb interaction, GGA+U calculation is also carried out and the HM property is ensured.

Electronic Structure and Ferromagnetic Properties of Doped Calcium Sulfide Ca1−xTMxS (TM = V, Cr and Co)

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050013 ◽  
Author(s):  
Amina Aiche ◽  
Abdelkader Tadjer ◽  
Hadj Moulay Ahmed Mazouz ◽  
Bendouma Doumi ◽  
Houari Khachai
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Double Exchange ◽  
Ferromagnetic State ◽  
Spin Splitting ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Half Metallic

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.

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.

scholarly journals Density functional studies of magneto-optic properties of Sr2GdReO6

2018 ◽  
Vol 4 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Saadi Berri ◽  
Sabah Chami ◽  
Mourad Attallah ◽  
Mouloud Oumertem ◽  
Djamel Maouche
Keyword(s):  
Density Functional ◽  
Interaction Mechanism ◽  
Double Perovskite ◽  
Full Potential ◽  
Ambient Conditions ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Double Exchange Interaction ◽  
Electronic Band ◽  
Magneto Optic

The electronic structure and magneto-optic properties of the Sr2GdReO6 double perovskite were investigated using the full-potential linearized augmented plane wave (FPLAPW) method. Exchange correlation effects are treated using the generalized gradient approximations GGA, GGA + U and GGA + U + SOC approachs. At ambient conditions, these calculation predict a half-metallic character for Sr2GdReO6 material. The electronic band structures and density of states demonstrate that Sr2GdReO6 is HM with a magnetic moment of 9 µB/fu and HM flip gap of 1.82 eV. The half metallicity is attributed by the double-exchange interaction mechanism via the Gd(4f)–O(2p)–Re(t2g) π-bounding. These new double perovskite may become ideal candidate material for future spintronic applications. The analysis charge densities show that bonding character as a mixture of covalent and ionic nature. The optical properties are analyzed and the origin of some peaks in the spectra is described. Besides, the dielectric function ε(ω), refractive index n (ω) and extinction coefficient K (ω) for radiation up to 14 eV have also been reported.

scholarly journals Half-metallic Ferromagnetism in Non-magnetic Double Perovskite Oxides Sr2MSbO6 (M=Al, Ga) Doped with C and N.

2021 ◽  
Author(s):  
AMRANI Bouhalouane ◽  
Djilali BENDJEBBOUR ◽  
Tayeb SEDDIK ◽  
Mohamed Walid MOHAMED ◽  
driss khdoja
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Double Perovskite ◽  
Perovskite Oxides ◽  
Full Potential ◽  
Double Perovskites ◽  
Generalized Gradient ◽  
Half Metallic ◽  
Impurity Bands ◽  
C And N

Abstract Double perovskite oxides have gained tremendous attention in material science and device technology due to their facile synthesis and exceptional physical properties. In this paper, we elucidate the origin of magnetization in non magnetic double perovskite oxides Sr2MSbO6 (M=Al, Ga) induced by non-magnetic 2p-impurities (C and N) substituted. The calculations were done within the full potential linearized augmented plane wave method (FP-LAPW) in the framework of the density functional theory (DFT). The exchange-correlation potential is evaluated using the generalized gradient approximation (GGA) of Perdew–Burke–Ernzerhof (PBE) and the modified Becke and Johnson (mBJ-GGA). Regarding structural properties of undoped double perovskites Sr2MSbO6 (M=Al, Ga), we found that the lattice constants and oxygen positions are in rational accord with the experimental results. Furthermore, both of the examined compounds are brittle in nature with isotropic character. For Sr2AlSbO6 we have got the values of energy gap equal to 1.9 eV and 3.7 eV within the GGA and the mBJ-GGA, respectively. However for Sr2GaSbO6 the values of energy gap obtained in GGA and mBJ-GGA are equal to 0.8 eV and 2.9 eV, respectively. Finally, spin-polarized calculations reveal that the doping C and N can lead to drastic changes in the magneto-electronic properties of the semiconducting Sr2MSbO6 matrix with the integer magnetic moment of 6.00 µB and exhibit half-metallic properties. The origin of ferromagnetism can be attributed to the spin–split impurity bands inside the energy gap of the semiconducting Sr2MSbO6 matrix. These results may help experimentalists in synthesizing new double perovskites for spintronic applications.

First-Principle Calculations of Half-Metallic Double Perovskite La2BB´O6(B,B´=3d transition metal)

2013 ◽  
Vol 14 (1) ◽  
pp. 174-185 ◽  
Author(s):  
Y. P. Liu ◽  
S. H. Chen ◽  
H. R. Fuh ◽  
Y. K. Wang
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Double Perovskite ◽  
Correlation Effect ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Full Structure ◽  
Magnetic States

AbstractIn this paper, we present calculations based on density functional theory using generalized gradient approximation (GGA) in double perovskite structure La2BB’O6 (B,B’ = 3d transition metal) out of combinational possibilities. Considering 4 types of magnetic states, namely, ferromagnetic (FM), ferrimagnetic (FiM), antiferromagnetics (AF), and nonmagnetic (NM) with full structure optimization, 13 possible surviving, stable FM/FiM-HM materials containing 6 FM-HM materials (La2ScNiO6, La2CrCoO6, La2CrNiO6, La2VScO6, La2VZnO6, and La2VNiO6) and 7 FiM-HM materials (La2VFeO6, La2ZnCoO6, La2TiCoO6, La2CrZnO6, La2CrMnO6, La2ScFeO6, and La2TiMnO6) are found. Considering the correlation effect (GGA+U), there are 6 possible half-metallic stable, surviving (HM) materials containing 3 FMHM materials (La2ScNiO6, La2CrCoO6, and La2CrNiO6) and 3 FiM-HM materials (La2VFeO6, La2ZnCoO6, and La2TiCoO6).

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 Electronic structure, Mechanical and Thermodynamic properties of CoYSb (Y= Cr, Mo, W) half-Heusler compounds as potential spintronic materials

2021 ◽  
Author(s):  
O. T. Uto ◽  
J. O. Akinlami ◽  
S. Kenmoe ◽  
G. A. Adebayo
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Phase ◽  
Covalent Bond ◽  
Stable Phase ◽  
Type I ◽  
Generalized Gradient ◽  
Electronic Density ◽  
Electronic Band ◽  
Half Metallic

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.

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