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.

Tunable Magnetism and Half-Metallic Stability in Si-Doped Hg2CuTi-Type Ti2CoGa Alloy

2012 ◽  
Vol 229-231 ◽  
pp. 130-133 ◽  
Author(s):  
Bo Wu ◽  
Yu Feng ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Density Functional ◽  
Magnetic Moments ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Lattice Constants ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Si Doped ◽  
Direct Hybridization

Using the ab-initio calculations within the density functional theory (DFT), we have investigated the electronic structure, magnetism and half-metallic stability of Si-doped Heusler compound Ti2CoGa with Hg2CuTi-type structure. The results revel that the lattice constants and total magnetic moments in per unit obey the Vegard’s rule and the Slater-Pauling rule well, respectively. The most stable half-metallicity occurs at doping concentration x=0.75 because the Fermi level is located at the middle of the spin-minority gap. 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.

Computational study of the optical properties of ZnS nanoparticles

2015 ◽  
Vol 1738 ◽  
Author(s):  
M. M. Sigalas
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Density Functional ◽  
Computational Study ◽  
Time Dependent ◽  
Generalized Gradient ◽  
Zns Nanoparticles ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

ABSTRACTUsing the density functional theory (DFT) and time dependent DFT, within the generalized gradient approximation (GGA), the electronic and optical properties of stoichiometric (ZnS)n nanoparticles (NP) were calculated. The dependence of the gap on the size (n) of the nanoparticle will be presented. The effect of replacing S atoms with P, Se or Te atoms in the (ZnS)n nanoparticles and its influence in the gap will be also shown.

DOPAMINE ADSORPTION CONFIGURATIONS ON ANATASE (101) SURFACE

2015 ◽  
Vol 22 (04) ◽  
pp. 1550052 ◽  
Author(s):  
ARVIDS STASHANS ◽  
FREDDY MARCILLO ◽  
DARWIN CASTILLO
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

Present work is based on the density functional theory (DFT) and generalized gradient approximation studies. Different adsorption geometries of dopamine, C 8 H 11 O 2 N , on the anatase (101) surface have been considered and carefully investigated. Bidentate chelating configuration with two molecular oxygens binding to the same surface titanium has been found to be the equilibrium case. The Ti – O distances for this configuration are obtained to be equal to 2.23 and 2.37 Å, respectively.

A Density Functional Study of Ho-Doped Sin (n=1-12, 16, and 18) Clusters

2011 ◽  
Vol 130-134 ◽  
pp. 1035-1038
Author(s):  
Zong Lin Liu ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Functional Study ◽  
Surface Site ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

The geometric, electronic, and magnetic properties of Ho-doped Sin (n=1-12, 16, and 18) clusters are studied via the density functional theory with the generalized gradient approximation. The results show that the Ho atom in the most stable HoSin clusters always occupies the surface site. Starting from n=18, the Ho atom abruptly drops into the center of Si frame, forming the Ho-encapsulated Si cages. The stabilities of HoSin clusters increase with increasing size n. The Ho atom in HoSin clusters enhances their chemical activities. Moreover, the magnetisms of HoSin clusters are independent of their geometric structures, and the Si and Ho atoms are antiferromagnetic.

Density functional theory studies on adsorption and decomposition mechanism of FOX-7 on Al13 clusters

2013 ◽  
Vol 91 (12) ◽  
pp. 1207-1212 ◽  
Author(s):  
Cai-Chao Ye ◽  
Feng-Qi Zhao ◽  
Si-Yu Xu ◽  
Xue-Hai Ju
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Aluminum Surface ◽  
Bond Breaking ◽  
Generalized Gradient ◽  
Aluminum Clusters ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory ◽  
Radical Fragment

The adsorption and decomposition of the FOX-7 molecule on Al13 clusters were investigated by generalized gradient approximation of the density functional theory. The strong attractive forces between the FOX-7 molecule and aluminum atoms induce the N−O bond breaking of FOX-7. Subsequently, the dissociated oxygen atoms and radical fragment of FOX-7 oxidize the aluminum clusters. The largest adsorption energy is −1020.4 kJ/mol. We also investigated three adsorption reaction paths of the FOX-7 molecule on the Al13 clusters in the A configuration. The activation energy for the adsorption steps are 0.2, 11.4, and 10.2 kJ/mol, respectively, and Al13 is more active than the Al(111) surface and the Al13 cluster performs better in decreasing the adsorption barrier of FOX-7 on the aluminum surface as well. The rate constants of three adsorption paths increase as temperature increases over the temperature range 275–500 K.

Density functional theory studies of methanol adsorption and decomposition mechanism on Al13 clusters

2014 ◽  
Vol 92 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Cai-Chao Ye ◽  
Feng-Qi Zhao ◽  
Si-Yu Xu ◽  
Xue-Hai Ju
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Reaction Pathways ◽  
Bond Dissociation Energies ◽  
Generalized Gradient ◽  
Aluminum Clusters ◽  
Functional Theory ◽  
Dissociation Energies ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

The adsorption and decomposition of the CH3OH molecule on Al13 clusters were investigated by generalized gradient approximation of the density functional theory. The strong attractive forces between the CH3OH molecule and aluminum atoms induce the breaking of the H–O and C–O bonds of CH3OH. Subsequently, the dissociated CH3O and OH radical fragments oxidize the aluminum clusters. The largest adsorption energy is –205.4 kJ/mol. We also investigated five reaction pathways of the CH3OH molecule on the Al13 clusters. The activation energies are in the range of 10.3−113.1 kJ/mol. Compared with the bond dissociation energies of the C–O and O–H bonds in the isolated methanol, Al13 performs very well in decreasing the bond break barrier of CH3OH. In addition, although the C–O bond is slightly weaker than the O−H bond, the O−H bond is even easier to decompose on the Al13 surface. The rate constants of five adsorption paths over the temperature range 300−700 K are presented.

Dissociation of dinitrogen on iron clusters: A detailed study of the Fe16 + N2 case.

2020 ◽  
Author(s):  
Bole Chen ◽  
Gennady L. Gutsev ◽  
Weiguo Sun ◽  
Xiao-Yu Kuang ◽  
Cheng Lu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Basis Set ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Iron Clusters ◽  
Generalized Gradient Approximation

The coalescence of two Fe8N as well as the structure of the Fe16N2 cluster were studied using density functional theory with the generalized gradient approximation and a basis set of...

scholarly journals Thermodynamics of Uranium Tri-Iodide from Density-Functional Theory

2020 ◽  
Vol 10 (11) ◽  
pp. 3914
Author(s):  
Per Söderlind ◽  
Aurélien Perron ◽  
Emily E. Moore ◽  
Alexander Landa ◽  
Tae Wook Heo
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Heat Capacity ◽  
Density Functional ◽  
Thermodynamic Assessment ◽  
Harmonic Approximation ◽  
Metallic System ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation

Density-functional theory (DFT) is employed to investigate the thermodynamic and ground-state properties of bulk uranium tri-iodide, UI3. The theory is fully relativistic and electron correlations, beyond the DFT and generalized gradient approximation, are addressed with orbital polarization. The electronic structure indicates anti-ferromagnetism, in agreement with neutron diffraction, with band gaps and a non-metallic system. Furthermore, the formation energy, atomic volume, crystal structure, and heat capacity are calculated in reasonable agreement with experiments, whereas for the elastic constants experimental data are unavailable for comparison. The thermodynamical properties are modeled within a quasi-harmonic approximation and the heat capacity and Gibbs free energy as functions of temperature agree with available calculation of phase diagram (CALPHAD) thermodynamic assessment of the experimental data.

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