scholarly journals Effect of H Adsorption on the Magnetic Properties of an Fe Island on a W(110) Surface

2019 ◽  
Author(s):  
Marko Melander ◽  
Hannes Jonsson
Keyword(s):  
Magnetic Properties ◽  
Data Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Low Dimensional ◽  
Low Dimensional Materials

<p>Low-dimensional materials, such as ultrathin films, nanoislands and wires, are actively being researched due to their interesting magnetic properties and possible technological applications for example in high density data storage. Results of calculations of an Fe nanoisland on a W(110) support are presented here with particular focus on the effect of hydrogen adsorption on its magnetic properties. This is an important consideration since hydrogen is present even under ultra-high vacuum conditions. The calculations are based on density functional theory within the generalized gradient approximation. The adsorption of H atoms is found to strongly decrease the magnetic moment of the Fe atoms they are bound to, down to less than a half in some cases as compared with the clean Fe island. The results show that it may be important to take the presence of hydrogen into account in measurements of magnetic properties of nanoislands.</p>

scholarly journals Effect of H Adsorption on the Magnetic Properties of an Fe Island on a W(110) Surface

2019 ◽  
Author(s):  
Marko Melander ◽  
Hannes Jonsson
Keyword(s):  
Magnetic Properties ◽  
Data Storage ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Low Dimensional ◽  
Low Dimensional Materials

<p>Low-dimensional materials, such as ultrathin films, nanoislands and wires, are actively being researched due to their interesting magnetic properties and possible technological applications for example in high density data storage. Results of calculations of an Fe nanoisland on a W(110) support are presented here with particular focus on the effect of hydrogen adsorption on its magnetic properties. This is an important consideration since hydrogen is present even under ultra-high vacuum conditions. The calculations are based on density functional theory within the generalized gradient approximation. The adsorption of H atoms is found to strongly decrease the magnetic moment of the Fe atoms they are bound to, down to less than a half in some cases as compared with the clean Fe island. The results show that it may be important to take the presence of hydrogen into account in measurements of magnetic properties of nanoislands.</p>

scholarly journals Structural, Electronic, and Magnetic Properties of Mn4N Perovskite: Density Functional Theory Calculations and Monte Carlo Study

2019 ◽  
Vol 33 (5) ◽  
pp. 1507-1512 ◽  
Author(s):  
A. Azouaoui ◽  
M. El Haoua ◽  
S. Salmi ◽  
A. El Grini ◽  
N. Benzakour ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Monte Carlo ◽  
Magnetic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Generalized Gradient ◽  
Critical Temperatures ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

AbstractIn this paper, we have studied the structural, electronic, and magnetic properties of the cubic perovskite system Mn4N using the first principles calculations based on density functional theory (DFT) with the generalized gradient approximation (GGA). The obtained data from DFT calculations are used as input data in Monte Carlo simulation with a mixed spin-5/2 and 1 Ising model to calculate the magnetic properties of this compound, such as the total, partial thermal magnetization, and the critical temperatures (TC). The obtained results show that Mn4N has a ferrimagnetic structure with two different sites of Mn in the lattice and presents a metallic behavior. The obtained TC is in good agreement with experimental results.

The structure, and electronic and magnetic properties of MX (M=GA, IN; X=S, SE, TE) nanoribbons

2020 ◽  
Vol 34 (18) ◽  
pp. 2050168
Author(s):  
Fei Feng ◽  
Fengdong Lv ◽  
Gongping Zheng ◽  
Guangtao Wang
Keyword(s):  
Magnetic Properties ◽  
Quantum Confinement ◽  
Density Functional ◽  
Quantum Confinement Effect ◽  
Ring Structure ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Semiconductor Behavior ◽  
Low Dimensional ◽  
Edge Side

We used the first principle of density functional theory to perform detailed calculations regarding the structure, and the electronic and magnetic properties of MX (M[Formula: see text]=[Formula: see text]Ga, In; X[Formula: see text]=[Formula: see text]S, Se, Te) nanoribbons. The armchair nanoribbons (ARNs) are nonmagnetic semiconductors, which have even or odd oscillations of bandgaps. All small-sized zigzag nanoribbons (ZRNs) were found to break the six-membered ring structure and move to the center, thereby exhibiting nonmagnetic semiconductor behavior owing to the quantum confinement effect. However, among the large ZRNs, which are all metals, MTe ZRNs are nonmagnetic; this differs from the case of graphene, MoS2 and Ti2CO2 nanoribbons. MX (M[Formula: see text]=[Formula: see text]Ga, In; X[Formula: see text]=[Formula: see text]S, Se) ZRNs exhibited ferromagnetism owing to the presence of the unpaired electrons on the metal-edge side and the magnetic moment of each pair of molecules, which was controlled by the size of the nanoribbons. The results provided a theoretical reference that can be used in the future to produce MX materials for application in low-dimensional semiconductor devices, spin electron transport devices and new magnetoresistance devices.

Density Functional Calculations on Electronic and Magnetic Properties of Fe-Pt Systems

2005 ◽  
Vol 475-479 ◽  
pp. 3103-3106 ◽  
Author(s):  
You Song Gu ◽  
Jian He ◽  
Zhen Ji ◽  
Xiao Yan Zhan ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moment ◽  
Electronic Structures ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Experimental Values ◽  
Pseudo Potential

The electronic structures and magnetic properties of Fe-Pt systems were calculated by CASTEP codes, which employed density functional theory, generalized gradient approximation (GGA), Perdew Burke Ernzerh exchange correlation, Pulay density-mixing scheme and Ultra Soft pseudo potential. The band structures and density of states (DOS) were calculated, together with band populations and magnetic properties. The calculated results of α-Fe show the validatiy of this method in predication magnetic properties. It is found that as the Pt concentration increases, Fe 4s and 3d electrons decrease while 4p electrons increase, and the magnetic moment of Fe atom increases. Pt atoms also contribute to the magnetic moment due to polarization. The calculated magnetization agrees with experimental values quite well.

Equilibrium geometries, electronic structure and magnetic properties of ConSn (n = 1–12) clusters from density functional calculations

2017 ◽  
Vol 31 (15) ◽  
pp. 1750171 ◽  
Author(s):  
Jing Ya Zhang ◽  
Jin Lv
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Density Of State ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Order Difference ◽  
Electron Density Functional Theory ◽  
External Site ◽  
Equilibrium Geometries ◽  
Stable Structures

Equilibrium geometries, relative stabilities, electronic stabilities and magnetic properties of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters have been systematically investigated by using relativistic all-electron density functional theory with generalized gradient approximation. The results indicated that the lowest-energy structures of Co[Formula: see text]Sn ([Formula: see text] = 1–5, 7, 9 and 10) clusters are similar to those of corresponding Co[Formula: see text] clusters. As for Co6Sn, Co8Sn, Co[Formula: see text]Sn and Co[Formula: see text]Sn clusters, the most stable structures give rise to a geometry reconstruction. In the low-lying structures of Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters, tin impurity prefers to occupy the external site. The second-order difference energy of the ground-state Co[Formula: see text]Sn ([Formula: see text] = 1–12) clusters shows a pronounced odd–even oscillation with the number of Co atoms, and the clusters exhibit higher stability at [Formula: see text] = 5. Compared with corresponding pure Co[Formula: see text] clusters, the total magnetic moment of the Co[Formula: see text]Sn clusters reduces with 1, 3 and 5 [Formula: see text], respectively. The different magnetic changes of the tin doped Co clusters are analyzed in detail based on the magnetism coupling, density of state and hybridization between cobalt and tin atoms.

Structures and electronic properties of WmCunH2 (m+n ≤ 7) clusters

2018 ◽  
Vol 32 (20) ◽  
pp. 1850209
Author(s):  
Zhicheng Yu ◽  
Xiurong Zhang ◽  
Kun Gao ◽  
Peiying Huo
Keyword(s):  
Hydrogen Storage ◽  
Electronic Properties ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Generalized Gradient ◽  
Functional Theory ◽  
High Thermodynamic Stability ◽  
Analysis Of Stability ◽  
Ground State Structures ◽  
Adsorption And Dissociation

Geometric and electronic structures of W[Formula: see text]Cu[Formula: see text]H2 (m + n [Formula: see text] 7) clusters have been systematically calculated by density functional theory (DFT) at the generalized gradient approximation (GGA) level for ground-state structures. For all W–Cu clusters, H atoms prefer to attach to W atoms in this system during adsorption. And more electrons transfer from H atom to W atom with the growth of the size of the cluster which benefits the hydrogen storage. Analysis of stability properties and electronic properties shows that hydrogen adsorption and dissociation process take place more efficiently at the W2Cu3H2 cluster than the others. Due to high thermodynamic stability and adsorption energy of W5CuH2 cluster among W[Formula: see text]Cu[Formula: see text]H2 (m + n [Formula: see text] 7) clusters, W5Cu is more suitable for hydrogen storage.

Magnetic Properties of Mn Doped NiO

2008 ◽  
Vol 55-57 ◽  
pp. 857-860 ◽  
Author(s):  
Ekaphan Swatsitang ◽  
A. Pimsawat
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Plane Wave ◽  
Density Functional ◽  
Program Package ◽  
Basis Set ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Mn Doped

ABINIT program package based on Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA) and plane wave basis set are used to calculate the magnetic properties of Mn doped NiO. It was found that the magnetic properties of Mn doped NiO were changed from anti-ferromagnetic (pure NiO) to ferromagnetism. Increasing the concentrations of Mn, the magnetization of Mn doped NiO were increased (Ni31MnO32 = 66.69 µB, Ni30Mn2O32 = 69.59 µB and Ni29Mn3O32 = 72.42 µB).

Density Functional Theory Study of GdnO3 (n=1-5) Clusters

2012 ◽  
Vol 588-589 ◽  
pp. 51-54
Author(s):  
Lin Xu ◽  
Zong Lin Liu ◽  
Hong Kuan Yuan
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Average Binding Energy ◽  
Generalized Gradient Approximation ◽  
Electronic Configurations ◽  
Homo Lumo

The geometries, stabilities, electronic and magnetic properties of small GdnO3(n=1-5) clusters have been systematically studied by using density functional theory with the generalized gradient approximation. We found that the Gd atoms and O atoms in GdnO3clusters prefer three and two coordination, respectively, which origin from the electronic configurations of Gd and O atoms. The results show that Gd2O3cluster is more stable than its respective neighbors, which is reflected from its high average binding energy and high HOMO-LUMO gap. In addition, we calculate the magnetic properties of GdnO3clusters. The local magnetic moments of the Gd atom in the GdnO3clusters exhibit a weak dependence on the O atoms, which are slightly enhanced with the increasing of the number of Gd atom.

A Density Functional Theory Study of Gd8O12 Cluster

2012 ◽  
Vol 542-543 ◽  
pp. 1418-1421
Author(s):  
Qing Xiang Gao ◽  
Lin Xu ◽  
Bo Wu
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Cage Structure ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Spin Polarized ◽  
Ionic Bonds

The spin-polarized generalized gradient approximation to the density functional theory is used to determine the geometries, stability, electronic structures, and magnetic properties of the Gd8O12cluster. Our work reveals that the ground state configuration of the Gd8O12cluster is a hexahedral cage structure with Cisymmetry. The electronic and magnetic properties imply that the formations of the ionic bonds between the adjacent Gd and O atoms result in the high stability of the Gd8O12cluster, which is due to the charge transfers between the Gd 5d, 6s electrons to O 2p orbital. It is also confirmed by the electron densities of HOMO-LUMO states. In addition, the analysis of the magnetic properties implies the total magnetic moments are mostly dominated by the Gd 4f orbital.

scholarly journals DFT-Mbj Study of Electronic and Magnetic Properties of Cubic Cecro3 Compound: An Ab-Initio Investigation

2017 ◽  
Vol 1 (1) ◽  
pp. 27-36
Author(s):  
M. Rashid ◽  
M. A. Iqbal ◽  
N. A. Noor
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Exchange Constant ◽  
Local Spin Density Approximation ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Exchange Constants ◽  
First Time

By considering density functional theory (DFT) in terms of ab-initio investigation, we have explored the structural, electronic and magnetic properties of cubic CeCrO3 for the first time. In order to determine the structural stability of cubic CeCrO3 compound, we optimized the structure of CeCrO3 in non-magnetic (NM), ferromagnetic (FM) and Anti-ferromagnetic (AFM) phases by using PBE generalized gradient approximation (GGA) functional to find the exchangecorrelation potential. From structural optimization, the FM phase of CeCrO3 is observed to be stable. For computing electronic and magnetic properties, thelately advanced modified Becke and Johnson local (spin) density approximation (mBJLDA) is used. Calculated band structures and density of states plots with an integer magnetic moment of 4 μB and reveal half-metallic character. In addition, s–d exchange constants (N0α) and p–d exchange constant (N0β) are determined, which are in agreement with a distinctive magneto-optical experiment.

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