Thermodynamic stability, half-metallic and optical nature of graphene-like Mn2 ZrZ (Z = Ge, Si): Ab initio study

2018 ◽  
Vol 32 (29) ◽  
pp. 1850324
Author(s):  
Arash Anjami ◽  
Arash Boochani ◽  
Seyed Mohammad Elahi ◽  
Hosein Akbari
Keyword(s):  
Density Functional ◽  
Ultra Violet ◽  
Refraction Index ◽  
Infrared Region ◽  
Full Potential ◽  
Metallic Behavior ◽  
Half Metallic ◽  
Optical Responses ◽  
Spin Polarized ◽  
Thermodynamic Phase

Half-metallic, optical and thermodynamic phase diagrams of two-dimensional Mn2ZrZ (Z = Ge, Si) have been calculated by density functional theory (DFT) framework with full-potential linear augmented plane-wave (FP-LAPW) method. The spin-polarized electronic computations show that these layers have metallic behavior with a spin polarization less than 100%. It is observed that with increasing thickness of the layers, both the thermodynamic and energy stabilities increased, and the graphene-like layers of Mn2ZrGe with a thickness of 7.6955 Å and Mn2ZrSi with a thickness of 7.551 Å are completely stable thermodynamically. The optical responses of Mn2ZrZ (Z = Ge, Si) have anisotropy at infrared region versus the optical direction and have high metallic nature in this optical range. The plasmonic frequencies have occurred after the visible edge and the refraction index becomes lower than one after the ultra-violet edge.

Ferrimagnetic Half-Metallicity of the New Quaternary Heusler Alloy CoCrScIn: FP-LAPW Method

SPIN ◽  
2021 ◽  
Vol 11 (02) ◽  
pp. 2150017
Author(s):  
Halima Hamada ◽  
Keltouma Boudia ◽  
Friha Khelfaoui ◽  
Kadda Amara ◽  
Toufik Nouri ◽  
...  
Keyword(s):  
Magnetic Moment ◽  
Density Functional ◽  
Structural Parameters ◽  
Magnetic Transition ◽  
Plane Waves ◽  
Full Potential ◽  
Half Metallicity ◽  
Metallic Behavior ◽  
Magnetic Transition Temperature ◽  
Half Metallic

The structural, electronic, elastic and magnetic properties of CoCrScIn were investigated using first principle calculations with applying the full-potential linearized augmented plane waves (FP-LAPW) method, based totally on the density functional theory (DFT). After evaluating the results, the calculated structural parameters reveal that CoCrScIn compound is stable in its ferrimagnetic configuration of the type-III structure. The mechanical properties show its brittle and stiffer behavior. The formation energy value showed that CoCrScIn can be experimentally synthesized. Additionally, the obtained band structures and density of states (DOS) reflect the half-metallic behavior of CoCrScIn, with an indirect bandgap of 0.43[Formula: see text]eV. The total magnetic moment of 3[Formula: see text][Formula: see text] and half-metallic ferrimagnetic state are maintained in the range 5.73–6,79 Å. The magnetic moment especially issues from the Cr-[Formula: see text] and Co-[Formula: see text] spin-polarizations. Furthermore, the calculations of Curie temperature reveal that CoCrScIn has high magnetic transition temperature of 836.7[Formula: see text]K.

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.

Investigation of the structural, electronic, elastic and thermodynamic properties of Curium Monopnictides: An ab initio study

2017 ◽  
Vol 31 (30) ◽  
pp. 1750226 ◽  
Author(s):  
H. Baaziz ◽  
Dj. Guendouz ◽  
Z. Charifi ◽  
S. Akbudak ◽  
G. Uğur ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Local Density ◽  
Structural Parameters ◽  
Structural Phase ◽  
Full Potential ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Spin Polarized

The structural, electronic, elastic and thermodynamic properties of Curium Monopnictides CmX (X = N, P, As, Sb and Bi) are investigated using first-principles calculations based on the density functional theory (DFT) and full potential linearized augmented plane wave (FP-LAPW) method under ambient condition and high pressure. The exchange-correlation term is treated using two approximations spin-polarized local density approximation (LSDA) and spin-polarized generalized gradient approximation generalized (GGA). The structural parameters such as the equilibrium lattice parameters, bulk modulus and the total energies are calculated in two phases: namely NaCl (B1) and CsCl (B2). The obtained results are compared with the previous theoretical and experimental results. A structural phase transition from B1 phase to B2 phase for Curium pnictides has been obtained. The highest transition pressure is 122 GPa for CmN and the lowest one is 10.0 GPa for CmBi compound. The electronic properties show that these materials exhibit half-metallic behavior in both phases. The magnetic moment is found to be around 7.0 [Formula: see text]B. The mechanical properties of CmX (X = N, P, As, Sb and Bi) are predicted from the calculated elastic constants. Our calculated results are in good agreement with the theoretical results in literature. The effect of pressure and temperature on the thermodynamic properties like the cell volume, bulk modulus and the specific heats C[Formula: see text] and C[Formula: see text], the entropy [Formula: see text] and the Grüneisen parameter [Formula: see text] have been foreseen at expanded pressure and temperature ranges.

Electronic structures, elastic, magnetic properties and half-metallicity in PtONa3 anti-perovskite

2019 ◽  
Vol 33 (29) ◽  
pp. 1950362 ◽  
Author(s):  
Oum Elkheir Youb ◽  
Zoubir Aziz ◽  
Feyza Zahira Meghoufel ◽  
Bouadjemi Boubdellah ◽  
Djoher Chenine ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Metallic Behavior ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Spin Polarized ◽  
Linearized Augmented Plane Wave

The structural, elastic, electronic and magnetic properties of the cubic [Formula: see text] anti-perovskite are investigated by means of the full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). We have used three approximations: the generalized gradient (GGA), the GGA+[Formula: see text][Formula: see text], where [Formula: see text] is on-site Coulomb interaction correction, and the modified Becke–Johnson (mBJ-GGA). The elastic constants [Formula: see text] show that our compounds are ductile and anisotropic. The results obtained for the spin-polarized band structure and the density of states show a half-metallic behavior for the compounds using the GGA, GGA+[Formula: see text][Formula: see text] and mBJ-GGA approaches. These results make [Formula: see text] a promising candidate for spintronics applications.

Structural, electronic, and magnetic properties of CrMnX (X = Ge, Se, Si, and Sn) compounds

2020 ◽  
Vol 98 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Shabbir Ahmed ◽  
M. Shakil ◽  
Muhammad Zafar ◽  
M.A. Choudhary ◽  
T. Iqbal
Keyword(s):  
Magnetic Properties ◽  
Bulk Modulus ◽  
Density Functional ◽  
Magnetic Moments ◽  
Compositional Variation ◽  
Band Structure Calculation ◽  
Full Potential ◽  
Metallic Behavior ◽  
Half Metallic ◽  
Electronic And Magnetic Properties

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.

Optical dispersion functions of Co2−xEuxVSn using ab-initio calculations

2015 ◽  
Vol 29 (28) ◽  
pp. 1550195 ◽  
Author(s):  
Nada T. Mahmoud ◽  
Ahmad A. Mousa ◽  
Hassan K. Juwhari ◽  
Jamil M. Khalifeh ◽  
Mohammed S. Abu-Jafar
Keyword(s):  
Density Functional ◽  
Ferromagnetic Material ◽  
Rare Earth Ions ◽  
Full Potential ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Half Metallic ◽  
Metallic Compounds ◽  
Optical Dielectric ◽  
Linearized Augmented Plane Wave

The magnetic, electronic and optical properties of [Formula: see text] alloys for selected concentrations (x = 0, 0.25, 0.50, 0.75 and 1.0) were investigated by means of density functional theory (DFT) calculations utilizing full potential linearized augmented plane wave (FP-LAPW) method. It was found that doping the [Formula: see text] alloy with rare-earth ions like Eu generates the nonstoichiometric [Formula: see text] and changes its original behavior from half ferromagnetic material to a metallic one. In addition, the total magnetic moment was found to increase with increasing dopant concentration with maximum local magnetic contributions on the Eu-sites. The optical dielectric functions as well as their static value for all the above alloys were also investigated. Moreover, the absorption coefficient, reflectivity and refractive indices were calculated. All the optical calculations were found to agree well with the band structure calculations when determining the alloys’ half-metallic behavior. Finally, the nonstoichiometric metallic compounds found in this series might be useful in the flat panel industry as potential phosphors.

Investigation of optoelectronic and thermoelectric properties of half-metallic BaRuO3 using DFT+U

2018 ◽  
Vol 07 (03) ◽  
pp. 1850018 ◽  
Author(s):  
A. Labdelli ◽  
A. Boukortt ◽  
S. Meskine ◽  
H. Abbassa ◽  
A. Zaoui
Keyword(s):  
Thermal Conductivity ◽  
Optical Properties ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Coulomb Repulsion ◽  
Full Potential ◽  
Thermoelectric Efficiency ◽  
Generalized Gradient ◽  
Metallic Behavior ◽  
Half Metallic

We have studied the structural, electronic, magnetic, thermoelectric and optical properties of the half-metal BaRuO3 using the accurate full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. The GGA[Formula: see text] approximation was also used to enhance the description of the electronic structure after calculating theoretically the Coulomb repulsion ([Formula: see text][Formula: see text]eV). The ferromagnetic (FM) phase of BaRuO3 is more stable. This result is in accordance with experimental and theoretical calculations. The calculated magnetic moments in BaRuO3 were found to arise especially from the Ru-4d state electrons. We have obtained the semiconductor gap (0.9[Formula: see text]eV) in spin-up while in spin down, the metal character was dominant, and therefore BaRuO3 has a half-metallic behavior. The thermoelectric efficiency was 0.12 at room temperature. Here we have considered only the electronic thermal conductivity, we have not included the lattice thermal conductivity. The relaxation time was assumed constant. The [Formula: see text] approximation was also used to analyze the optical properties by determining the complex dielectric function from which are derived the other parameters.

scholarly journals The effect of pressure and alloying on half-metallicity of quaternary Heusler compounds CoMnYZ (Z = Al, Ga, and In)

2016 ◽  
Vol 34 (4) ◽  
pp. 905-915 ◽  
Author(s):  
M. Rahmoune ◽  
A. Chahed ◽  
A. Amar ◽  
H. Rozale ◽  
A. Lakdja ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Heusler Alloys ◽  
Band Gaps ◽  
Ferromagnetic Behavior ◽  
Full Potential ◽  
Energy Bands ◽  
Half Metallicity ◽  
Half Metallic ◽  
Electronic And Magnetic Properties

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).

Ab-Initio Investigation of Strain Effects on the Physical Properties of PdVTe Alloy

2021 ◽  
Author(s):  
Khodja Djamila ◽  
Djaafri Tayeb ◽  
Djaafri Abdelkader ◽  
Bendjedid Aicha ◽  
Hamada Khelifa ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Of States ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Full Potential ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Strain Effects ◽  
Half Metallic

The investigations of the strain effects on magnetism, elasticity, electronic, optical and thermodynamic properties of PdVTe half-Heusler alloy are carried out using the most accurate methods to electronic band structure, i.e. the full-potential linearized augmented plane wave plus a local orbital (FP-LAPW + lo) approach. The analysis of the band structures and the density of states reveals the Half-metallic behavior with a small indirect band gap Eg of 0.51 eV around the Fermi level for the minority spin channels. The study of magnetic properties led to the predicted value of total magnetic moment µtot = 3µB, which nicely follows the Slater–Pauling rule µtot = Zt -18. Several optical properties are calculated for the first time and the predicted values are in line with the Penn model. It is shown from the imaginary part of the complex dielectric function that the investigated alloy is optically metallic. The variations of thermodynamic parameters calculated using the quasi-harmonic Debye model, accord well with the results predicted by the Debye theory. Moreover, the dynamical stability of the investigated alloy is computed by means of the phonon dispersion curves, the density of states, and the formation energies. Finally, the analysis of the strain effects reveals that PdVTe alloy preserves its ferromagnetic half metallic behavior, it remains mechanically stable, the ionic nature dominates the atomic bonding, and the thermodynamic and the optical properties keep the same features in a large interval of pressure.

DFT study of elastic, half-metallic and optical properties of Co2V(Al, Ge, Ga and Si) compounds

2017 ◽  
Vol 31 (14) ◽  
pp. 1750109 ◽  
Author(s):  
Heidar Khosravi ◽  
Arash Boochani ◽  
Golnaz Rasolian ◽  
Shahram Solaymani ◽  
Sirvan Naderi
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Elastic Stability ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Spin Mode ◽  
Half Metallic ◽  
Lattice Constants ◽  
Optical Treatment

First-principles study of elastic, electronic and optical properties of full-Heusler Co2V(Al, Ge, Ga and Si) compounds are calculated through density functional theory (DFT) to obtain and compare the mentioned properties. Equilibrium lattice constants of these compounds are in good agreement with other works. Electronic calculations are shown full spin polarization at Fermi level for all compounds, so in the down spin, indirect bandgap is calculated as 0.33, 0.6, 0.2 and 0.8 eV for Co2V(Al, Ge, Ga and Si), respectively. The integer amounts of the magnetic moments are compatible with Slater–Pauling role. The optical treatment of Co2VGa is different from three other compounds. All mentioned compounds have metallic behavior by 22 eV plasmonic frequency. The imaginary part of the dielectric function for the up spin indicates that the main optical transitions occurred in this spin mode. Moreover, the elastic results show that the Co2VGa does not have elastic stability, but the other three compounds have fully elastic stability and the Co2V(Al, Ge and Si) belong to the hardness of materials.

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