The Adsorption of NH3 on the FeS2 (100) Surface: A First-Principles Investigation

2020 ◽  
Vol 1001 ◽  
pp. 22-27
Author(s):  
Chong Liang ◽  
Xin Lu Liu ◽  
Li Che ◽  
Kun Yang
Keyword(s):  
Density Of States ◽  
First Principles ◽  
Steric Repulsion ◽  
First Principles Calculations ◽  
Partial Coverage ◽  
Full Coverage ◽  
Strong Hybridization ◽  
Adsorption Energies

Using first-principles calculations, we have investigated the adsorption of NHx (x =1, 2 or 3) on the FeS2 (100) surface. The adsorption configurations and adsorption energies were determined. Our calculations showed that the NHx prefers to adsorb on the surface Fe site via N atom. The NH molecule displays the strongest interaction with the FeS2 (100) surface among the three adsorbates, while NH3 is bound relatively weak to the surface. The analysis of the density of states (DOS) showed a strong hybridization between N 2p and Fe 3d states, especially for NH and NH2 adsorption. The NH3 adsorption at full coverage was found to be less favoured than at partial coverage because of the steric repulsion among the adsorbates, in agreement with the experiment.

scholarly journals Origin of the Dzyaloshinskii-Moriya Interactions in the Intermetallic RMn2Si2 ( R= La, Ce, Yb and Y) Materials: A DFT Study

2021 ◽  
Author(s):  
Widad Bazine ◽  
Najim TAHIRI ◽  
Omar Elbounagui ◽  
Hamid Ez-Zahraouy
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Density Of States ◽  
First Principles ◽  
Giant Magnetoresistance ◽  
Dft Study ◽  
Spin Orbit ◽  
First Principles Calculations ◽  
Strong Hybridization ◽  
Large Spin

Abstract The Dzyaloshinskii-Moriya interactions (DM) are investigated using first-principles calculations by means of the WIENNCM code, an implementation of the FP-LAPW method. The intermetallic RMn2Si2 (R = La, Ce, Yb, and Y) materials exhibit a large spin-orbit effect after the density of states; they found a strong hybridization between Mn-Si and Mn-R atoms. Also, show a large noncollinear magnetic configuration depending on the R atoms. By using ab-initio calculations, the RKKY effect is observed in the RMn2Si2 materials, which shows explicitly the existence of the giant magnetoresistance (GMR) in these materials. Explicitly, the mechanisms responsible for the magnetoelectric coupling are due to relatively the effect of the presence of the Dzyaloshinskii-Moriya term.

First-principles study on the stability and magnetoelectric properties of multiferroic materials XTiO3 (X = Mn, Fe, Co, Ni)

2018 ◽  
Vol 32 (09) ◽  
pp. 1850105 ◽  
Author(s):  
Xing-Yuan Chen ◽  
Guo-Xia Lai ◽  
Di Gu ◽  
Wei-Ling Zhu ◽  
Tian-Shu Lai ◽  
...  
Keyword(s):  
Magnetic Property ◽  
First Principles ◽  
Phonon Dispersion ◽  
Critical Conditions ◽  
First Principles Calculations ◽  
Multiferroic Materials ◽  
Equilibrium Conditions ◽  
Magnetoelectric Properties ◽  
Strong Hybridization ◽  
The Stability

The XTiO3 (X = Mn, Fe, Co and Ni) materials with R3c structure could be grown under critical conditions based on first-principles calculations and thermodynamic stability analysis. FeTiO3 and MnTiO3 could be synthesized relatively easily under metal-rich and O-poor conditions, while NiTiO3 could be stable under Ni-rich, O-rich and Ti-poor conditions. The predicted R3c CoTiO3 under thermodynamic equilibrium conditions is suggested to be synthesized under Co-rich, O-rich and Ti-poor conditions, but the calculated phonon dispersion indicates R3c CoTiO3 becomes unstable under the dynamical conditions. The ferroelectric behavior in the XTiO3 (X = Mn, Fe, Co and Ni) system could be dominated by the Ti ion with d0 state and the strong hybridization between Ti and O, while the magnetic property is mainly caused by the contribution of 3d transition metal.

Oxide Thermoelectrics

2007 ◽  
Vol 1044 ◽  
Author(s):  
David Joseph Singh
Keyword(s):  
First Principles ◽  
Transport Theory ◽  
Point Of View ◽  
First Principles Calculations ◽  
Boltzmann Transport ◽  
Oxide Thermoelectrics ◽  
Seebeck Coefficients ◽  
Boltzmann Transport Theory ◽  
Strong Hybridization ◽  
Narrow Bands

AbstractThermoelectricity in oxides, especially NaxCoO2 and related materials, is discussed from the point of view of first principles calculations and Boltzmann transport theory. The electronic structure of this material is exceptional in that it has a combination of very narrow bands and strong hybridization between metal d states and ligand p states. As shown within the framework of conventional Boltzmann transport theory, this leads to high Seebeck coefficients even at metallic carrier densities. This suggests a strategy of searching for other narrow band oxides that can be doped metallic with mobile carriers. Some possible avenues for finding such materials are suggested.

First-Principles Study on the Clean and Nb Doped TiO2(110)γ-TiAl(111) Interfaces

2012 ◽  
Vol 602-604 ◽  
pp. 555-558 ◽  
Author(s):  
Hui Nan Hao ◽  
Xu Wang ◽  
Fu He Wang
Keyword(s):  
Structural Stability ◽  
Density Of States ◽  
Chemical Bonding ◽  
First Principles ◽  
Adhesion Energy ◽  
First Principles Calculations ◽  
First Principles Study

In this paper, the structural stability, adhesion and chemical bonding of the TiO2 (110)/TiAl (111) interface are investigated by the first-principles calculations. We predict the maximum adhesion energy of 1.91J/m2 of the TiO2/TiAl interface. We also calculated the Nb doped interface, and found that the doped Nb atom prefers to replace the Ti atom at the second layer of TiAl slab. The atomic geometry and density of states are analyzed. The results show that the effect of doped Nb is localized and insignificant on the TiO2 (110)/TiAl(111) interface.

Structural phase transition, electronic, elastic, and vibrational properties of LiAl intermetallic compound: insights from first-principles calculations

2017 ◽  
Vol 95 (8) ◽  
pp. 691-698
Author(s):  
Y. Mogulkoc ◽  
Y.O. Ciftci ◽  
G. Surucu
Keyword(s):  
Phase Transition ◽  
Density Of States ◽  
Structural Phase Transition ◽  
First Principles ◽  
Density Functional ◽  
Structural Phase ◽  
Type Structure ◽  
Vibrational Properties ◽  
First Principles Calculations ◽  
Electronic Band

Using the first-principles calculations based on density functional theory (DFT), the structural, elastic, electronic, and vibrational properties of LiAl have been explored within the generalized gradient approximation (GGA) using the Vienna ab initio simulation package (VASP). The results demonstrate that LiAl compound is stable in the NaTl-type structure (B32) at ambient pressure, which is in good agreement with the experimental results and there is a structural phase transition from NaTl-type structure (B32) to CsCl-type structure (B2) at around 22.2 GPa pressure value. The pressure effects on the elastic properties have been discussed and the elastic property calculation indicates that the elastic instability could provide a phase transition driving force according to the variations relation of the elastic constant versus pressure. To gain further information about this, we also have investigated the other elastic parameters (i.e., Zener anisotropy factor, Poisson’s ratio, Young’s modulus, and isotropic shear modulus). The electronic band structure, total and partial density of states, phonon dispersion curves, and one-phonon density of states of B2 and B32 phases are also presented with results.

Grain Refining Behavior of Zr, Al2Y and Al4C3 Particles in Magnesium Alloys by the First-Principles Calculations

2015 ◽  
Vol 816 ◽  
pp. 370-374
Author(s):  
Jun Ling Pan ◽  
Qiu Ming Peng ◽  
Jian Xin Guo ◽  
Hui Li
Keyword(s):  
Mechanical Properties ◽  
Structural Optimization ◽  
Magnesium Alloys ◽  
Density Of States ◽  
Adsorption Energy ◽  
First Principles ◽  
Adsorption Process ◽  
Mg Alloys ◽  
Grain Refining ◽  
First Principles Calculations

Grain refining is one of the most important issues in the applications of Mg alloys, which directly determines mechanical properties and deformability. Therefore the understanding of grain refining mechanism during solidification will be benefit to develop new grain refiners. Herein refining role was elucidated by the first principles calculations based on adsorption behavior of a Mg atom on the closest-packed planes of grain refiners (Zr (001), Al2Y(311) and Al4C3(102)). Taking into account different sites, the site with the maximum adsorption energy value generally corresponded to the most possible location. The adsorption energy results show that the possible refining turn follows Al4C3(102)>Zr (001)>Al2Y(311). Meanwhile, the structural optimization confirmed that the Mg atom connected with two C atoms on the top of zig-zag plane of Al4C3(102), three Zr atoms at the hcp position on Zr (001), and two Y atoms and one Al atom at the bottom of zig-zag plane of Al2Y(311). The density of states revealed that the variation of d-orbital electrons of Mg atom became apparent during adsorption process. The values of Mulliken charges were 0.898 e in Al4C3(102), 0.410 e in Zr (001) and 0.245 e in Al2Y(311), respectively. This tendency agrees well with the previous experimental results. It indicates the adsorption energy on the closest-packed planes can be regarded as a prerequisite to select new grain refiners for Mg alloys in future.

Electronic properties and lattice configurations of Au/CH3NH3PbI3 interface

2017 ◽  
Vol 31 (18) ◽  
pp. 1750199 ◽  
Author(s):  
F. J. Si ◽  
W. Hu ◽  
F. L. Tang ◽  
Y. W. Cheng ◽  
H. T. Xue
Keyword(s):  
Binding Energy ◽  
Charge Density ◽  
Density Of States ◽  
First Principles ◽  
Lattice Mismatch ◽  
Lattice Structure ◽  
Electronic States ◽  
Density Difference ◽  
First Principles Calculations ◽  
Charge Density Difference

The lattice structure, interface binding energy, density of states, charge density difference and Bader charges of Au (100)/CH3NH3PbI3 (MAPbI3) (100) interface were studied with the first-principles calculations. The lattice mismatch of the Au (100)/MAPbI3 (100) interface is 3.48%. The interface binding energy is −0.124 J/m2. There is a small amount of electronic states nearby the interface through analyzing the density of states of the interface. In addition, the atom orbital has hybridizations nearby the interface. Through analyzing charge density difference and Bader charges, it is found that there is obvious charge transfer at the interface.

First-Principles Calculations of C2H4 Adsorption on Pd Surface Stacked on Fcc-Au

2010 ◽  
Vol 654-656 ◽  
pp. 1666-1669
Author(s):  
Noboru Taguchi ◽  
Shingo Tanaka ◽  
Tomoki Akita ◽  
Masanori Kohyama ◽  
Fuminobu Hori
Keyword(s):  
Density Of States ◽  
Atomic Structure ◽  
First Principles ◽  
Partial Density ◽  
First Principles Calculations ◽  
Slab Surface ◽  
Adsorption Model ◽  
Partial Density Of States ◽  
Projector Augmented Wave

We performed first-principles calculations of stable atomic structure and partial density of states (PDOS) analysis of Ethylene (C2H4) adsorption on Pd(100) surface stacked on fcc-Au using the projector augmented-wave (PAW) method. In case of Pd overlayers on the Au(100) substrate, from the analysis of PDOS around surface, highest occupied states become sharpen compared with the case of C2H4 adsorption on Pd monometallic slab surface in both di- and  adsorption model.

Density of States of Co- and Cr-Doped Ni2.0Mn1.5Sn0.5 Heusler Alloys

2016 ◽  
Vol 845 ◽  
pp. 162-165
Author(s):  
Mikhail A. Zagrebin ◽  
Vladimir V. Sokolovskiy ◽  
Vasiliy D. Buchelnikov ◽  
Marina A. Klyuchnikova
Keyword(s):  
Spin Polarization ◽  
Density Of States ◽  
Magnetic Moment ◽  
First Principles ◽  
Heusler Alloys ◽  
Coherent Potential Approximation ◽  
First Principles Calculations ◽  
Potential Approximation ◽  
Co Concentration ◽  
Co Concentrations

The composition dependences of the density of states in Co- and Cr-doped Ni-Mn-Sn Heusler alloys are investigated by using first principles calculations. The off-stoichiometric compositions are realized by the coherent-potential approximation. We have shown that the spin polarization decreases with increasing Cr and Co concentrations. While, the total magnetic moment was found to decrease (increase) with increasing Cr (Co) concentration, respectively.

Sign in / Sign up

Export Citation Format

Share Document