Electronic and magnetic properties of bulk and surfaces half-Heusler alloy KCaB and its bulk thermoelectric properties

2021 ◽  
pp. 2150258
Author(s):  
Jabbar M. Khalaf Al-zyadi ◽  
Wed A. Abed ◽  
Ahmed Hamad Ati
Keyword(s):  
Magnetic Moment ◽  
Heusler Alloy ◽  
Density Functional ◽  
Energy Gap ◽  
Relaxation Effect ◽  
First Principles Calculation ◽  
Half Metallic ◽  
Text Type ◽  
Electronic Spin ◽  
Metallic Ferromagnet

This paper discusses the structural, electronic, magnetic, and half-metallic properties of half-Heusler alloy KCaB. First-principles calculation based on density functional theory is successfully used to determine properties at bulk and on the (111) and (001) surfaces of KCaB. KCaB is half-metallic ferromagnet with a magnetic moment of 1 [Formula: see text] and an energy gap equal to 0.82 eV in the lower spin channel. The [Formula: see text]-type doped exhibits higher Seebeck coefficient, electrical conductivity, thermal conductivity, and figure of merit than the [Formula: see text]-type-doped KCaB at room-temperature 300 K. The half-metallic property is preserved in each of the ends Ca and B on the (111) surface and is lost in the ends K (111) and B and KCa (001) slab surface. The relaxation effect on the electronic spin states decreases the magnetic moment of some atoms on the end surface because the relaxation of the atomic sites is affected and the loss of the nearest neighbors affects exchange–correlation interactions. The surface end with Ca is more stable than the surface end with B on the (111) surface and can maintain the property of half metallic under relatively large stress.

Theoretical investigation of the electronic and thermoelectric behavior of CoV2O4 alloy

2019 ◽  
Vol 08 (02) ◽  
pp. 1950008
Author(s):  
Mahmoud Al-Elaimi ◽  
Farida Hamioud ◽  
G. I. Ameereh ◽  
A. A. Mubarak
Keyword(s):  
Thermoelectric Properties ◽  
Ground State ◽  
Density Functional ◽  
Charge Carriers ◽  
Functional Theory ◽  
Half Metallic ◽  
Text Type ◽  
Present Alloy ◽  
Metallic Ferromagnet ◽  
Sound Velocities

Density functional theory (DFT) within Wien2k code is utilized to compute the mechanical, thermal, electronic, magnetic and thermoelectric properties of the cubic spinel CoV2O4. The ground state lattice constant of CoV2O4 alloy agrees with previous literature. The calculated elastic constants of CoV2O4 predict that the present alloy is anisotropic, elastically stable and brittle. Beneficial acoustical applications are expected for the present alloy due to its high calculated Debye temperature and average sound velocities values. The longitudinal and transverse sound velocities modes of vibrations are found maximum along [110] directions compared to [100] and [111] directions. The calculated DOS and band structure show that CoV2O4 is electronically stable. The present alloy possesses a total magnetic moment of 12.0 [Formula: see text] and is classified as a half-metallic ferromagnet. CoV2O4 shows [Formula: see text]-type behavior and favors holes as charge carriers. The present alloy owns beneficial thermoelectric properties and can be used in thermoelectric applications.

Electronic and Magnetic Properties of Half Metallic Heusler Alloy Co2mnsi: A First-Principles Study

2017 ◽  
pp. 31-36
Author(s):  
Prakash Sharma ◽  
Gopi Chandra Kaphle
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Heusler Alloy ◽  
Density Functional ◽  
Heusler Alloys ◽  
Tight Binding ◽  
Lattice Parameter ◽  
Half Metallic ◽  
Electronic And Magnetic Properties ◽  
Sphere Approximation

Heusler alloys have been of great interest because of their application in the field of modern technological word. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co2MnSi 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 Co2MnSi are found to be 2.52A0 , 3.49A0 , 5.50A0 , 5.53A0 respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co2MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co2MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co2MnSi are magnetic with magnetic moment 2.85μB and 4.91μB respectively. The contribution of orbitals in band, DOS and magnetic moment are due to d-orbitals of Co and Mn and little from s and p-orbital of Si in Co2MnSi.The Himalayan Physics Vol. 6 & 7, April 2017 (31-36)

Mxene Monolayer Mn2ZnN2: A Promising Robust Intrinsic Half-metallic Nanosheet

2021 ◽  
Author(s):  
Huang Cheng-Cai ◽  
Wang Yang ◽  
Yao Qian ◽  
Dengfeng Li ◽  
Liu Jun
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Electrode Materials ◽  
Energy Gap ◽  
Two Dimensions ◽  
Half Metallicity ◽  
Half Metallic ◽  
Spin Polarized ◽  
Metallic Ferromagnet ◽  
A Charge

Abstract Two-dimensions half-metallic ferromagnet is more promising in spintronics. In recent years, the half-metallicity and the magnetic properties of the Mxene materials have been the research hotspot of new materials due to their unique crystal characteristics and wide promising applications. In this paper, the geometric structure of the Mxene nanosheet Mn2ZnN2 was optimized, and then its electric and magnetic properties were studied by the first principles calculations. Results show that the Mxene nanosheet Mn2ZnN2 is possibly a kind of robust intrinsic half-metallic nanosheet with the integer magnetic moment 6.00 μB per unit. Its half-metallic character and the magnetic moment mainly come from the spin-polarized Mn-ions induced by the crystal field. If the absolute compression stain is lower 3.0 %, its half-metallicity remains well and the magnetic moment per unit is always 6.00 μB, indicating its half-metallicity and magnetic properties are stable to some extent. More importantly, removing an electron from this nanosheet, its magnetic moment per unit increases from 6.00 μB to 9.00 μB and the half-metallic energy gap of its spin-down subband increase evidently, showing that removing a charge from the nanosheet may improve evidently its half-metallicity and magnetic properties. Therefore, this nanosheet may be one of preferred spintronic electrode materials.

scholarly journals First-principles calculations of magnetic and mechanical properties of Fe-based nanocrystalline alloy Fe80Si10Nb6B2Cu2

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chong Sun ◽  
Zhengang Shi ◽  
Wenjie Fu ◽  
Linhao Zhang ◽  
Han Li ◽  
...  
Keyword(s):  
Band Structure ◽  
Magnetic Moment ◽  
First Principles ◽  
Density Functional ◽  
Energy Gap ◽  
Population Analysis ◽  
Decisive Role ◽  
Nanocrystalline Alloy ◽  
State Density ◽  
First Principles Calculation

Abstract Based on the first-principles calculation method of density functional theory (DFT), the crystal structure, band structure, magnetic moment, density of state, elastic constant and population analysis of Fe80Si10Nb6B2Cu2 are calculated. The calculation results show that the Fe-based nanocrystalline alloy of this composition has a stable structure, strong resistance to deformation, high hardness and is an alloy with good flexibility. The energy band structure of spin-up and spin-down is basically the same, and the energy gap is 0 eV, showing metallicity. The asymmetry of the electronic state density between the spin-up and spin-down states indicates that the alloy is ferromagnetic, with a magnetic moment of 84.15 μ; the Fe element plays a decisive role in the magnetic properties of this alloy.

THE FIRST PRINCIPLES CALCULATION OF STRUCTURAL, ELECTRONIC AND MAGNETIC PROPERTIES OF MnXY (X = Ru, Rh AND Y = Ga, Ge, Sb) ALLOYS

2011 ◽  
Vol 25 (26) ◽  
pp. 2079-2090 ◽  
Author(s):  
S. M. MONIRI ◽  
Z. NOURBAKHSH ◽  
M. MOSTAJABODAAVATI
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Density Functional ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Local Magnetic Moment ◽  
First Principles Calculation ◽  
Functional Theory ◽  
Half Metallic ◽  
Electronic And Magnetic Properties

The structural, electronic and magnetic properties of MnXY ( X = Ru , Rh and Y = Ga , Ge , Sb ) Heusler alloys are studied using density functional theory by the WIEN2k package. These materials are ferromagnetic. Also they have some interesting half-metallic properties. The electron density of states, total and local magnetic moment of these alloys are calculated. We have calculated the effective Coulomb interaction U eff using the ab initio method. We have compared the magnetic moments of these alloys in GGA and LDA + U with the Slater–Pauling rule. Furthermore the effect of hydrostatic pressure on the magnetic moment of these alloys is studied. The calculated results are fitted with a second order polynomial.

Study of Co2MnAl Heusler alloy as half metallic ferromagnet

2010 ◽  
Vol 84 (6) ◽  
pp. 717-721 ◽  
Author(s):  
Dibya Prakash Rai ◽  
Javad Hashemifar ◽  
Morteeza Jamal ◽  
Lalmuanpuia ◽  
M. P. Ghimire ◽  
...  
Keyword(s):  
Heusler Alloy ◽  
Half Metallic ◽  
Metallic Ferromagnet

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.

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.

scholarly journals Spin Gapless Semiconductor–Nonmagnetic Semiconductor Transitions in Fe-Doped Ti2CoSi: First-Principle Calculations

2018 ◽  
Vol 8 (11) ◽  
pp. 2200 ◽  
Author(s):  
Yu Feng ◽  
Zhou Cui ◽  
Ming-sheng Wei ◽  
Bo Wu ◽  
Sikander Azam
Keyword(s):  
Magnetic Moment ◽  
Electronic Structures ◽  
Magnetic Moments ◽  
Total Magnetic Moment ◽  
First Principle ◽  
Half Metallic ◽  
Heusler Compound ◽  
First Principle Calculations ◽  
Metallic Ferromagnet

Employing first-principle calculations, we investigated the influence of the impurity, Fe atom, on magnetism and electronic structures of Heusler compound Ti2CoSi, which is a spin gapless semiconductor (SGS). When the impurity, Fe atom, intervened, Ti2CoSi lost its SGS property. As TiA atoms (which locate at (0, 0, 0) site) are completely occupied by Fe, the compound converts to half-metallic ferromagnet (HMF) TiFeCoSi. During this SGS→HMF transition, the total magnetic moment linearly decreases as Fe concentration increases, following the Slate–Pauling rule well. When all Co atoms are substituted by Fe, the compound converts to nonmagnetic semiconductor Fe2TiSi. During this HMF→nonmagnetic semiconductor transition, when Fe concentration y ranges from y = 0.125 to y = 0.625, the magnetic moment of Fe atom is positive and linearly decreases, while those of impurity Fe and TiB (which locate at (0.25, 0.25, 0.25) site) are negative and linearly increase. When the impurity Fe concentration reaches up to y = 1, the magnetic moments of Ti, Fe, and Si return to zero, and the compound is a nonmagnetic semiconductor.

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