Physical Properties of RhCrZ (Z= Si, Ge, P, As) Half-Heusler Compounds: A First-Principles Study

2020 ◽  
Vol 13 (1) ◽  
pp. 29-46
Keyword(s):  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
Structural Parameters ◽  
Mean Field Approximation ◽  
Cubic Phase ◽  
Full Potential ◽  
Heusler Compounds ◽  
Half Metallicity ◽  
Half Metallic

We use the first-principles-based density functional theory with full potential linearized augmented plane wave method in order to investigate the structural, elastic, electronic, magnetic and thermoelectric properties of RhCrZ (Z= Si, Ge, P, As) Half-Heusler compounds. The preferred configurations of the RhCrZ alloys are all type a. The structural parameters are in good agreement with the available theoretical results. The Young’s and shear modulus, Poisson’s ratio, sound velocities, Debye temperature and melting temperature have been calculated. Furthermore, the elastic constants Cij and the related elastic moduli confirm their stability in the cubic phase and demonstrate their ductile nature. The compounds RhCrSi, RhCrGe, RhCrP and RhCrAs are found to be half-metallic ferrimagnets (HMFs) with a half-metallic gap EHM of 0.37, 0.35, 0.25 and 0.02 eV, respectively. The half-metallicity of RhCrZ (Z= Si, Ge, P, As) compounds can be kept in a quite large hydrostatic strain and tetragonal distortion. The Curie temperatures of RhCrSi, RhCrGe, RhCrP and RhCrAs compounds are estimated to be 952, 1261, 82 and 297 K, respectively, in the mean field approximation (MFA). Thermoelectric properties of the RhCrZ (Z= Si, Ge, P, As) materials are additionally computed over an extensive variety of temperatures and it is discovered that RhCrAs demonstrates higher figure of merit than RhCrSi, RhCrGe and RhCrP. The properties of half-metallicity and higher Seebeck coefficient make this material a promising candidate for thermoelectric and spintronic device applications

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.

First-principles study of electronic, optical and thermoelectric properties in cubic perovskite materials AgMO3 (M = V, Nb, Ta)

2014 ◽  
Vol 28 (10) ◽  
pp. 1450077 ◽  
Author(s):  
Asif Mahmood ◽  
Shahid M. Ramay ◽  
Hafiz Muhammad Rafique ◽  
Yousef Al-Zaghayer ◽  
Salah Ud-Din Khan
Keyword(s):  
Thermoelectric Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Perovskite Materials ◽  
Linearized Augmented Plane Wave

In this paper, first-principles calculations of structural, electronic, optical and thermoelectric properties of AgMO 3 ( M = V , Nb and Ta ) have been carried out using full potential linearized augmented plane wave plus local orbitals method ( FP - LAPW + lo ) and BoltzTraP code within the framework of density functional theory (DFT). The calculated structural parameters are found to agree well with the experimental data, while the electronic band structure indicates that AgNbO 3 and AgTaO 3 are semiconductors with indirect bandgaps of 1.60 eV and 1.64 eV, respectively, between the occupied O 2p and unoccupied d states of Nb and Ta . On the other hand, AgVO 3 is found metallic due to the overlapping behavior of states across the Fermi level. Furthermore, optical properties, such as dielectric function, absorption coefficient, optical reflectivity, refractive index and extinction coefficient of AgNbO 3 and AgTaO 3, are calculated for incident photon energy up to 50 eV. Finally, we calculate thermo power for AgNbO 3 and AgTaO 3 at fixed doping 1019 cm-3. Electron doped thermo power of AgNbO 3 shows significant increase over AgTaO 3 with temperature.

scholarly journals Structural, magneto-electronic and thermophysical properties of the new d0 quaternary heusler compounds KSrCZ (Z =P, As, Sb)

2020 ◽  
Vol 66 (3 May-Jun) ◽  
pp. 265
Author(s):  
A. Taleb ◽  
A. Chahed ◽  
M. Boukli ◽  
H. Rozale ◽  
B. Amrani ◽  
...  
Keyword(s):  
Density Functional ◽  
Full Potential ◽  
Heusler Compounds ◽  
Half Metallicity ◽  
Half Metallic ◽  
Plane Wave Method ◽  
Physical Response ◽  
Device Applications ◽  
Frame Work ◽  
Linearized Augmented Plane Wave

Investigation of band structure and thermo-physical response of the d0 new quaternary Heusler compounds KSrCZ (Z = P, As, Sb) within the frame work of density functional theory with full potential linearized augmented plane wave method has been analyzed. Results showed that type-Y3 is the most favorable atomic arrangement. All the compounds are found to be half-metallic ferromagnetic materials with an integer magnetic moment of 2.00 μB and a half-metallic gap EHM of 0.292, 0.234, and 0.351 eV, respectively. The half-metallicity of KSrCZ (Z = P, As, Sb) compounds can be kept in a quite large hydrostatic strain. Thermoelectric properties of the KSrCZ (Z = P, As, Sb) materials are additionally computed over an extensive variety of temperature and it is discovered that all compounds demonstrates higher figure of merit. The properties of half-metallicity and higher Seebeck coefficient makes these materials a promising candidates for thermoelectric and spintronic device applications. 

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).

First-Principles Study of the New Half-Metallic Ferromagnetic Quaternary-Heusler Alloys NaXNO (X=Ca, Sr, Ba)

SPIN ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 2050022 ◽  
Author(s):  
K. Belkacem ◽  
Y. Zaoui ◽  
S. Amari ◽  
L. Beldi ◽  
B. Bouhafs
Keyword(s):  
Magnetic Properties ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Heusler Alloys ◽  
Exchange Potential ◽  
Energy Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Half Metallic

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.

Pressure-Induced Tunable Magnetism and Half-Metallic Stability in Co2FeGa Heusler Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1303-1306
Author(s):  
Qin Xiang Gao
Keyword(s):  
Fermi Level ◽  
First Principles ◽  
Density Functional ◽  
High Energy ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
The Density Functional Theory

Using the first-principles calculations within the density functional theory (DFT), we have investigated the structure, magnetism and half-metallic stability of Co2FeGa Heusler compound under pressure from 0 to 50GPa. The results revel that the lattice constant is gradually shrank and total magnetic moment in per unit slightly decreased with increasing pressure, respectively. Moreover, with the increase of the pressure, the Fermi level will move towards high-energy orientation. When the pressure reaches at 30GPa the most stable half-metallicity is observed which the Fermi level is located at the middle of the spin-minority gap.

Prediction of half-metallicity in the NaS, NaSe and NaTe alkali-metal chalcogenides using first principles

2018 ◽  
Vol 07 (03) ◽  
pp. 1850015 ◽  
Author(s):  
H. Sadouki ◽  
A. Belkadi ◽  
Y. Zaoui ◽  
S. Amari ◽  
K. O. Obodo ◽  
...  
Keyword(s):  
Alkali Metal ◽  
First Principles ◽  
Density Functional ◽  
Theoretical Data ◽  
Stable Phase ◽  
Full Potential ◽  
Metal Chalcogenides ◽  
Electronic Band ◽  
Half Metallic ◽  
Binary Compounds

First-principles full-potential linearized augmented plane-wave method based on density functional theory is used to investigate the structural, electronic and magnetic properties of NaS, NaSe and NaTe alkali-metal chalcogenides binary compounds. These compounds in different crystalline phases: NaCl (B1), CsCl (B2), ZB (B3), NiAs (B81), WZ (B4) and Pnma were calculated within the generalized gradient approximation (GGA-PBE) and the modified Becke–Johnson approach (mBJ-GGA-PBE) for the exchange-correlation energy and potential. We found that the most stable phase for the NaX binary compounds is the nonmagnetic Pnma phase. The calculated lattice parameters, bulk moduli, their first-pressure derivatives and internal parameters are in good agreement with the other theoretical data. The electronic band structure and density of states show that half-metallic and magnetic character arises, which can be attributed to the presence of spin-polarized [Formula: see text] orbitals in the group VI elements. The NaS, NaSe and NaTe binary compounds show half-metallic character in ZB and WZ phases, with an integer magnetic moment of 1 [Formula: see text] per formula unit and half-metallic gaps.

The mechanical, optical and thermoelectric properties of MCoF3 (M = K and Rb) compounds

2017 ◽  
Vol 31 (06) ◽  
pp. 1750033 ◽  
Author(s):  
A. A. Mubarak
Keyword(s):  
Thermoelectric Properties ◽  
Density Functional ◽  
Full Potential ◽  
Functional Theory ◽  
Half Metallic ◽  
Augmented Plane Wave ◽  
The Density Functional Theory ◽  
Type Character ◽  
P Type ◽  
Linearized Augmented Plane Wave

This is an ab initio study instituted on the density functional theory (DFT) and the full-potential linearized augmented plane wave (FP-LAPW) calculations that are performed to analyze the mechanical, electronic, optical and thermoelectric properties of the cubic MCoF3 compound (M = K and Rb). The studied compounds are found thermodynamically and mechanically stable. Moreover, these compounds are found to be elastically anisotropic and ductile. KCoF3 and RbCoF3 are classified as half-metallic and anti-ferromagnetic compounds. The optical properties are investigated from the dielectric function for the different energy ranges. The thermoelectric properties such as transport properties are determined as a function of temperature using BoltzTrape code in the range of 20–800 K. The present compounds are found to have p-type character. Also, the majority charge carriers are found to be electrons rather than hole. Useful mechanical, spintronic, optical and thermoelectric applications are predicted based upon the calculations.

Half-metallicity and optoelectronic properties of V-doped zincblende ZnS and CdS alloys

2016 ◽  
Vol 30 (08) ◽  
pp. 1650034 ◽  
Author(s):  
Mohammed El Amine Monir ◽  
H. Baltache ◽  
R. Khenata ◽  
G. Murtaza ◽  
R. Ahmed ◽  
...  
Keyword(s):  
Magnetic Moment ◽  
Density Functional ◽  
Spin Exchange ◽  
Electronic Band Structure ◽  
Magnetic Behavior ◽  
Full Potential ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Electronic Band ◽  
Half Metallic

In this paper, spin-polarized density functional calculations on the structural, electronic, optical and magnetic properties of the zincblende structure of the [Formula: see text] and [Formula: see text] alloys at [Formula: see text] in the ferromagnetic (FM) ordering has been investigated. The study is accomplished using the full-potential (FP) linearized augmented plane wave plus local orbital (LAPW[Formula: see text]lo) self-consistent scheme of calculations. To incorporate the exchange correlation component in the total energy calculations of the crystal, Perdew–Burke and Ernzerhof (PBE) parameterization for the generalized gradient approximation (GGA) and GGA[Formula: see text]U are employed. Basically, for both alloys, to address their structural properties, we calculated their equilibrium lattice constants, bulk moduli as well as pressure derivatives. In general, from the analysis of the obtained electronic band structure of these alloys, the half-metallic nature of [Formula: see text] and nearly half-metallic nature of the [Formula: see text] alloy are demonstrated. The plotted density of states (DOS) curves project spin-exchange splitting energy [Formula: see text] and [Formula: see text] as generated by V-3d states. It has been clearly evident that the effective potential results for the spin-down case are more striking than for the spin-up case. In order to describe the magnetic behavior of these alloys, the exchange constants [Formula: see text] (valence band) and [Formula: see text] (conduction band) as well as the magnetic moment values are estimated. The calculated results of the magnetic moment show that the main source in the reduction of the local magnetic moment of V in the alloys in comparison with its free value is a [Formula: see text]–[Formula: see text] orbital hybridization and partial transfer to nonmagnetic sites of (Zn, S) and (Cd, S) in [Formula: see text] and [Formula: see text] alloys. In addition, a study concerning optical properties, such as the refractive index, reflectivity and absorption coefficients is performed to determine their potential for optical and optoelectronic devices.

scholarly journals Theoretical Investigations on the Mechanical, Magneto-Electronic Properties and Half-Metallic Characteristics of ZrRhTiZ (Z = Al, Ga) Quaternary Heusler Compounds

2019 ◽  
Vol 9 (5) ◽  
pp. 883 ◽  
Author(s):  
Wenbin Liu ◽  
Xiaoming Zhang ◽  
Hongying Jia ◽  
Rabah Khenata ◽  
Xuefang Dai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Total Magnetic Moment ◽  
Heusler Compounds ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Theoretical Investigations ◽  
Valence Electrons

The electronic, magnetic, and mechanical properties were investigated for ZrRhTiZ (Z = Al, Ga) quaternary Heusler compounds by employing first-principles calculations framed fundamentally within density functional theory (DFT). The obtained electronic structures revealed that both compounds have half-metallic characteristics by showing 100% spin polarization near the Fermi level. The half-metallicity is robust to the tetragonal distortion and uniform strain of the lattice. The total magnetic moment is 2 μB per formula unit and obeys the Slater-Pauling rule, Mt = Zt − 18 (Mt and Zt represent for the total magnetic moment and the number of total valence electrons in per unit cell, respectively). The elastic constants, formation energy, and cohesive energy were also theoretically calculated to help understand the possibility of experimental synthesis and the mechanical properties of these two compounds.

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