Ab Initio Calculations of Magnetic Properties of Perovskite Surfaces and Heterostructures

2016 ◽  
Vol 845 ◽  
pp. 105-110 ◽  
Author(s):  
Sergey Dunaevsky ◽  
Evgeny Mikhailenko
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Ultrathin Films ◽  
Density Functional ◽  
Magnetic Moments ◽  
Surface Layers ◽  
Functional Theory ◽  
Local Moments ◽  
Spin Polarized ◽  
Total Energies

The results of "ab-initio" calculations of spin - polarized electronic structure, total energy and the local atomic magnetic moments of some manganite surfaces are presented. A slab consisting of one, three, five or, in some cases, seven layers of Mn-O atoms. is used to model the CaMnO3 (CMO), LaMnO3 (LMO) (001) surface. Total energies calculations of magnetic properties of manganites surfaces were performed using density-functional theory (DFT) and the pseudopotential method. We have found that on the surface layers without structural optimization manganese atomic magnetic moment is higher than in the bulk and “dead layers”, where all the local moments are zero, have not been found. All the above ultrathin films appeared ferromagnetic semimetals with almost complete polarization of DOS near the Fermi level.

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 Computational Study of the Structural, Electronic and Magnetic Properties of Nanoclusters of Cu2O and CuO: Ab-Initio Approach

2020 ◽  
Vol 6 (1) ◽  
pp. 68-72
Author(s):  
T. P. Yadav ◽  
G. C. Kaphle ◽  
A. Srivastava
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Computational Study ◽  
Magnetic Moments ◽  
Minimum Energy ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Electronic And Magnetic Properties ◽  
Ab Initio Approach

The structural, electronic and magnetic properties of the nanoclusters of (Cu2O) n= 1, 2, 3 and (CuO) m = 2, 4, 6 have computationally studied. Density Functional Theory incorporated in Atomistic tool kit (ATK-DFT) calculators with exchange-correlation functional (SGGA+U) based ab-initio approach is applied for simulation and calculation of these nanoclusters. In the computational study, the nanoclusters (Cu2O)1, (Cu2O)3 , (CuO)2 and (CuO)6 show semiconducting behavior whereas (Cu2O)2 and (CuO)4 show semi-metallic behaviors. The nanoclusters (Cu2 O)1 and (Cu2O)3 show diamagnetic, (Cu2O)2 and (CuO)4 show ferromagnetic, (CuO)2 and (CuO)6 show antiferromagnetic behaviors. The magnetic moments 0.28μB and 0.03 μB are observed in the nanoclusters (Cu2O)2 and (CuO)4 while others are found to be as nonmagnetic . The total energy of nanoclusters have found to be decreasing towards total minimum energy with increasing number of atoms of copper oxides. The nanoclusters (Cu2O) n = 1, 2, 3 and (CuO) m = 2, 4, 6 are used in various applications as in the synthesis of technological materials. The analysis of the effects of bond length and binding energy with the size of nanoclsters have been presented.

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

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.

scholarly journals Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1059 ◽  
Author(s):  
Ivana Miháliková ◽  
Martin Friák ◽  
Yvonna Jirásková ◽  
David Holec ◽  
Nikola Koutná ◽  
...  
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Nearest Neighbor ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Α Phase ◽  
Ordered Intermetallic ◽  
Random Structures ◽  
The Impact

Quantum-mechanical calculations are applied to examine magnetic and electronic properties of phases appearing in binary Fe-Al-based nanocomposites. The calculations are carried out using the Vienna Ab-initio Simulation Package which implements density functional theory and generalized gradient approximation. The focus is on a disordered solid solution with 18.75 at. % Al in body-centered-cubic ferromagnetic iron, so-called α -phase, and an ordered intermetallic compound Fe 3 Al with the D0 3 structure. In order to reveal the impact of the actual atomic distribution in the disordered Fe-Al α -phase three different special quasi-random structures with or without the 1st and/or 2nd nearest-neighbor Al-Al pairs are used. According to our calculations, energy decreases when eliminating the 1st and 2nd nearest neighbor Al-Al pairs. On the other hand, the local magnetic moments of the Fe atoms decrease with Al concentration in the 1st coordination sphere and increase if the concentration of Al atoms increases in the 2nd one. Furthermore, when simulating Fe-Al/Fe 3 Al nanocomposites (superlattices), changes of local magnetic moments of the Fe atoms up to 0.5 μ B are predicted. These changes very sensitively depend on both the distribution of atoms and the crystallographic orientation of the interfaces.

Structural and Magnetic Properties of Mn2NiZ (Z = Ga, In, Sn, Sb) Heusler Alloys from Ab Initio Calculations

2015 ◽  
Vol 233-234 ◽  
pp. 229-232 ◽  
Author(s):  
Vladimir V. Sokolovskiy ◽  
Mikhail A. Zagrebin ◽  
Y.A. Sokolovskaya ◽  
Vasiliy D. Buchelnikov
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Heusler Alloys ◽  
Martensitic Transition ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Magnetic Properties ◽  
Structure Calculations ◽  
Good Agreement

The structural and magnetic properties of Mn-based stoichiometric Heusler alloys have investigated by means of ab initio calculations in framework of the density functional theory. First principles electronic structure calculations have shown that Mn2NiZ (Z = Ga, In, Sn, Sb) alloys are ferrimagnets with antiparallel alignment between the Mn atoms. The martensitic transition can be realized in Mn2NiGa and Mn2NiSn alloys with tetragonal ratio of 1.27 and 1.16, respectively. Calculated properties are in a good agreement with available experimental data.

scholarly journals Electronic and Magnetic Properties of Bulk and Monolayer CrSi2: A First-Principle Study

2018 ◽  
Vol 8 (10) ◽  
pp. 1885 ◽  
Author(s):  
Shaobo Chen ◽  
Ying Chen ◽  
Wanjun Yan ◽  
Shiyun Zhou ◽  
Xinmao Qin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Phonon Dispersion ◽  
First Principle ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Phonon Dispersion Curves ◽  
Electronic And Magnetic Properties ◽  
Quantum Size ◽  
Spin Polarized

We investigated the electronic and magnetic properties of bulk and monolayer CrSi2 using first-principle methods based on spin-polarized density functional theory. The phonon dispersion, electronic structures, and magnetism of bulk and monolayer CrSi2 were scientifically studied. Calculated phonon dispersion curves indicated that both bulk and monolayer CrSi2 were structurally stable. Our calculations revealed that bulk CrSi2 was an indirect gap nonmagnetic semiconductor, with 0.376 eV band gap. However, monolayer CrSi2 had metallic and ferromagnetic (FM) characters. Both surface and confinement effects played an important role in the metallic behavior of monolayer CrSi2. In addition, we also calculated the magnetic moment of unit cell of 2D multilayer CrSi2 nanosheets with different layers. The results showed that magnetism of CrSi2 nanosheets was attributed to band energy between layers, quantum size, and surface effects.

The ab initio density functional theory applied for spin-polarized calculations

2020 ◽  
Vol 152 (5) ◽  
pp. 054109 ◽  
Author(s):  
Szymon Śmiga ◽  
Volodymyr Marusiak ◽  
Ireneusz Grabowski ◽  
Eduardo Fabiano
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Functional Theory ◽  
Spin Polarized

Hydrogen Stabilization of {111} Nanodiamond

2002 ◽  
Vol 740 ◽  
Author(s):  
A.S. Barnard ◽  
N.A. Marks ◽  
S.P. Russo ◽  
I.K. Snook
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Size Range ◽  
Nanocrystalline Diamond ◽  
Surface Layers ◽  
Functional Theory ◽  
Wannier Functions ◽  
Carbon Onion ◽  
Interlayer Bonding

ABSTRACTPresented here are results of ab initio Density Functional Theory (DFT) structural relaxations performed on dehydrogenated and monohydrogenated nanocrystalline diamond structures of octahedral {111} and cuboctahedral morphologies, up to approximately 2nm in diameter. Our results in this size range show a transition of dehydrogenated nanodiamond clusters into carbon onion-like structures, with preferential exfoliation of the C(111) surfaces, in agreement with experimental observations. However, we have found that this transition may be prevented by hydrogenation of the surfaces. Bonding between atoms in the surface layers of the relaxed structures, and interlayer bonding has been investigated using Wannier functions.

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