AB INITIO STUDY OF STRUCTURAL STABILITY AND MAGNETIC PROPERTIES OF Con(n = 2 - 10): A STUDY BASED ON PSEUDOPOTENTIALS DFT

2011 ◽  
Vol 22 (04) ◽  
pp. 359-369
Author(s):  
M. SAMAH ◽  
B. MOULA
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Ground State ◽  
Density Functional ◽  
Magnetic Moments ◽  
Stability Study ◽  
Ab Initio Study ◽  
Functional Theory ◽  
The Stability ◽  
Magic Cluster

The lowest-energy geometric and isomers of freestanding Co n clusters (n = 2 - 10) and their corresponding magnetic moments have been studied using the Siesta code based on pseudopotential density-functional theory. The calculated results show that there are many isomers near the ground state. Different isomers hold different magnetic moment. The stability study shows that among the investigated clusters, the hexamer one is the most stable and is the magic cluster. Dissociation channels energy are also studied.

Stability, Electronic and Magnetic Properties of Ca3Ru2O7

2011 ◽  
Vol 217-218 ◽  
pp. 924-929
Author(s):  
Jin Hong Xue ◽  
Jing Chao Chen ◽  
Jie Yu ◽  
Jing Feng ◽  
Yong Pan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Cohesive Energy ◽  
Density Functional ◽  
Theoretical Study ◽  
Magnetic Moments ◽  
Covalent Bonds ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
The Stability

Ca3Ru2O7 is new tpye of thermoelectric materials.A theoretical study is presented for the stability, electronic and magnetic properties of three phases of this new thermoelectric materials in the framework of density functional theory (DFT). The calculated cohesive energy is -7.94eV/unit. AFM2 are less stable than other pahses. Electronic calculations indicate that Ca3Ru2O7 is metallic in nature. The covalent bonds in these structures are due to orbital overlap between p bands of O and d bands of Ru, and DOS at Fermi level are dominated by d bands of Ru. FM phase have obvious magnetic moments.

Magnetism and Half-Metallicity in (100) Surface of Inverse Heusler Mn2CoSb

2014 ◽  
Vol 1015 ◽  
pp. 377-380
Author(s):  
Tao Chen ◽  
Ying Chen ◽  
Yin Zhou ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
First Principles ◽  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
Surface States ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Functional Theory

Using the first-principles calculations within density functional theory (DFT), we investigated the electronic and magnetic properties of (100) surface of inverse Heusler alloy Mn2CoSb with five different terminations. Our work reveals that the surface Mn atom moves to vacuum while surface Co atom moves to slab. Moreover, duo to the reason that the surface atom lost half of the nearest atoms with respect to the bulk phase, resulting in the decrease of hybridization, the atom-resolved spin magnetic moments of surface atoms are enhanced. Further investigation on DOS and PDOS showed that half-metallicity was preserved only in SbSb-termination while was destroyed in MnCo-, MnSb-, MnMn-, and CoCo-termination due to the appearance of surface states.

Ab Initio Calculations of Electronic and Magnetic Properties of AlMnO3 Perovskite Manganites

2015 ◽  
Vol 754-755 ◽  
pp. 757-761
Author(s):  
Abdullah Chik ◽  
S. Saad ◽  
Cheow Keat Yeoh ◽  
R.M. Zaki ◽  
F. Che Pa
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Ground State ◽  
Density Functional ◽  
Covalent Bonding ◽  
Perovskite Manganites ◽  
Functional Theory ◽  
Cubic Crystal ◽  
Energy Approximation

The electronic structure of the perovskite manganites AlMnO3cubic crystal was presented. The calculations were made within density functional theory and PBE exchange correlations energy approximation. It was found that the crystal exhibit covalent bonding between Mn and O with superexchange mechanism. At groundstate, AlMnO3stabilizes in antiferromagnetic structure with semi metallic like nature at the ground state.

scholarly journals Electronic structure of the PrNiBi half-Heusler system based on the σGGA + U method

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
L. Mikaeilzadeh ◽  
A. Tavana ◽  
F. Khoeini
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Structure ◽  
Ground State ◽  
Density Functional ◽  
Functional Theory ◽  
Band Inversion ◽  
Topological State ◽  
Antiferromagnetic Ground State

AbstractIn this works, we study the electronic structure and magnetic properties of the Pr-Ni-Bi half-Heusler systems based on density functional theory. We use the σ GGA + U scheme to consider the effects of on-site electron-electron interactions. Results show that in contrast to the rough estimation of the total magnetic moment of the unit cell, based on the Slater-Pauling behavior in the half-Heusler systems, this system has an antiferromagnetic ground state because of the localized Pr-f electrons. By increasing the magnitude of the effective U parameter, band-inversion occurs in the band structure of this system, which shows the possibility of topological state occurrence.

Density functional theory study of transition metals doped B80 fullerene

2014 ◽  
Vol 13 (06) ◽  
pp. 1450050 ◽  
Author(s):  
Jianguang Wang ◽  
Li Ma ◽  
Yanhua Liang ◽  
Meiling Gao ◽  
Guanghou Wang
Keyword(s):  
Density Functional Theory ◽  
Outer Surface ◽  
Density Functional ◽  
Formation Energy ◽  
Magnetic Moments ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Energy Gaps ◽  
The Stability

Density functional theory calculations have been carried out to investigate 3d, Pd and Pt transition metal (TM) atoms exohedrally and endohedrally doped B 80 fullerene. We find that the most preferred doping site of the TM atom gradually moves from the outer surface ( TM = Sc ), to the inner surface ( TM = Ti and V ) and the center ( TM = Cr , Mn , Fe and Zn ), then to the outer surface ( TM = Co , Ni , Cu , Pd , and Pt ) again with the TM atom varying from Sc to Pt . From the formation energy calculations, we find that doping TM atom can further improve the stability of B 80 fullerene. The magnetic moments of doped V , Cr , Mn , Fe , Co and Ni atoms are reduced from their free-atom values and other TM atoms are completely quenched. Charge transfer and hybridization between 4s and 3d states of TM and 2s and 2p states of B were observed. The energy gaps of TM @ B 80 are usually smaller than that of the pure B 80. Endohedrally doped B 80 fullerene with two Mn and two Fe atoms were also considered, respectively. It is found that the antiferromagnetic (AFM) state is more energetically favorable than the ferromagnetic (FM) state for Mn 2- and Fe 2@ B 80. The Mn and Fe atoms carry the residual magnetic moments of ~ 3 μB and 2 μB in the AFM states.

Phase Stability Study of the Shape Memory Alloy CuAl-X (X: Be, Zn, Ti, Ni, Ag and Au) by Ab Initio Calculations

2016 ◽  
Vol 879 ◽  
pp. 250-255
Author(s):  
Nassim Boudalia ◽  
Jean Marc Raulot ◽  
Etienne Patoor ◽  
Claude Esling
Keyword(s):  
Density Functional Theory ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
First Principles ◽  
Density Functional ◽  
Dft Method ◽  
Stability Study ◽  
Atomic Scale ◽  
Functional Theory ◽  
The Stability

Shape memory alloys (SMA) have been at the forefront of research in recent years. They have been used for a wide variety of applications in various fields. This work presents a brief study at the atomic scale of Cu-Al based Shape Memory Alloys. Using first-principles Density Functional Theory (DFT) method, the stability of different austenitic and martensitic phases of Cu3Al, the effect of intrinsic vacancies, the doping effect by an element X (X = Be, Zn, Ti, Ni, Ag and Au) have been studied.

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 Rethinking the Magnetic Properties of Lepidocrocite: A Density Functional Theory and Cluster Expansion Study

2020 ◽  
Author(s):  
Daniel Pope ◽  
Aurora Clark ◽  
Micah Prange ◽  
Kevin Rosso
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Cluster Expansion ◽  
Ground State ◽  
Density Functional ◽  
Configuration Model ◽  
Electronic Density ◽  
Functional Theory ◽  
Lattice Constants ◽  
Subsequent Calculation

<div> <div> <div> <p>The iron oxyhydroxide lepidocrocite (γ-FeOOH) is an abundant mineral critical to a number of chemical and technological applications. Of particular interest is the ground state and finite temperature magnetic order, and the subsequent impact this has upon crystal properties. The magnetic properties, investigated in this work are governed primarily through superexchange interactions, and have been calculated using density functional theory and cluster expansion methods. Quantification of these exchange terms has facilitated the determination of the ground state magneto-crystalline structure and subsequent calculation of its lattice constants, elastic moduli, cohesive enthalpy, and electronic density of states. Further, using a collinear magnetic configuration model, the magnetic heat capacity versus temperature has been studied and the N ́eel temperature obtained. </p> </div> </div> </div>

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