Doping a Correlated Band Insulator: A New Route to Half-Metallic Behavior

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.

Download Full-text

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

SPIN ◽

10.1142/s201032472150017x ◽

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.

Download Full-text

Observation of intrinsic half-metallic behavior of CrO 2 (100) epitaxial films by bulk-sensitive spin-resolved PES

Journal of Electron Spectroscopy and Related Phenomena ◽

10.1016/j.elspec.2017.02.003 ◽

2017 ◽

Vol 220 ◽

pp. 46-49 ◽

Cited By ~ 2

Author(s):

Hirokazu Fujiwara ◽

Masanori Sunagawa ◽

Kensei Terashima ◽

Tomoko Kittaka ◽

Takanori Wakita ◽

...

Keyword(s):

Epitaxial Films ◽

Metallic Behavior ◽

Half Metallic

Download Full-text

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

International Journal of Modern Physics B ◽

10.1142/s0217979217501090 ◽

2017 ◽

Vol 31 (14) ◽

pp. 1750109 ◽

Cited By ~ 3

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.

Download Full-text

DFT study of structural, elastic, electronic, magnetic, thermal and transport properties of new multifunctional NiVSn half-Heusler for spintronic and thermoelectric applications

International Journal of Modern Physics B ◽

10.1142/s0217979221502027 ◽

2021 ◽

pp. 2150202

Author(s):

Y. Bouldiab ◽

S. terkhi ◽

Z. Aziz ◽

F. Bendahma ◽

M. A. Bennani ◽

...

Keyword(s):

Transport Properties ◽

Thermoelectric Properties ◽

Density Functional ◽

Extreme Temperature ◽

Ferromagnetic State ◽

Debye Model ◽

Generalized Gradient ◽

Metallic Behavior ◽

Half Metallic ◽

High Seebeck Coefficient

In this work, the first-principles density functional calculations of the structural, elastic, electronic, magnetic, thermal and thermoelectric properties of NiVSn half-Heusler compound are carried out. The exchange and correlation potential are treated by using Generalized Gradient approximation of Perdew, Burke and Ernzerhof (GGA-PBE), GGA plus Tran–Blaha-modified Becke–Johnson (mBJ-GGA) approach and mBJ-GGA+U where U is the Hubbard on-site Coulomb interaction correction (mBJ-GGA+U). Structural calculations revealed that NiVSn is stable in type 1 structure ferromagnetic state. Elastic properties show that our compound is mechanically stable, ductile and anisotropic. The results of the band structures and density of states display a half metallic behavior of NiVSn with an indirect bandgap of 0.476, 0.508 and 0.845 eV by using GGA-PBE, mBJ-GGA, and mBJ-GGA+U, respectively. The total magnetic moment calculated is integer of 1 [Formula: see text]B confirming a half metallic behavior of NiVSn and follows the well-known Slater–Pauling rule ([Formula: see text]); therefore, the studied compound is suitable for application in spintronic fields. The thermodynamic properties such as bulk modulus, the heat capacity, the Debye temperature, and the thermal expansion coefficient are investigated using quasi-harmonic Debye model (QHDM). The thermal results show that NiVSn can be applied in extreme temperature and pressure conditions. The thermoelectric properties are studied employing the BoltzTrap code. The calculated transport properties are very interesting for the spin-down channel with high electrical conductivity, high Seebeck coefficient, and figure of merit value approaching unity. As a result, the half-Heusler alloy NiVSn is a promoter for conventional thermoelectric materials.

Download Full-text

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

SPIN ◽

10.1142/s2010324720500137 ◽

2020 ◽

Vol 10 (02) ◽

pp. 2050013 ◽

Cited By ~ 1

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.

Download Full-text