Electronic Structure and Magnetism

2021 ◽  
pp. 173-384
Author(s):  
Jürgen Kübler
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Giant Magnetoresistance ◽  
Berry Phase ◽  
Magnetic Moments ◽  
Relativistic Effects ◽  
Anomalous Hall Effect ◽  
Transition Elements ◽  
Metal Compounds ◽  
Photoemission Data

The fundamental magnetic properties of iron, cobalt, and nickel are the center of interest, beginning with historical attempts and Stoner’s theory. Stoner susceptibility is derived in a modern way by Janak finding that only those three carry a magnetic moment in elementary metals. The energy-band structures of all transition elements are connected with their repective phase stability which is obtained by means of density-functional calculations. The band structure of the ferromagnetic metals is obtained and compared with angle-resolved photoemission data. The electronic structure of the antiferromagnetic metals, Cr, Mn, and fcc Fe is clarified. Next, the magnetic moments of transition-metal compounds are classified by means of the Slater–Pauling curve and a large number of compounds are half-metallic supplying spin-polarized transport. Multilayers realize oscillatory exchange and show unusual electronic properties such as giant magnetoresistance which is discussed in detail. Tunnel junctions supply spin valves. Relativistic effects in solids are of importance for magnetocrystalline anisotropy and spectroscopic effects. Kubo theory supplies the basic understanding of the magneto-optical Kerr effect for which a number of examples are given. Noncollinear magnetic order reveals novel interaction mechanisms, such as the Dzyaloshinsky–Moriya interaction. The Berry phase explains the anomalous Hall effect as well as the Nernst effect and leads to the field of topology in the solid state. Weyl fermions are also explored.

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.

scholarly journals Relativistic Effects on the Equation-of-State of the Light Actinides

2005 ◽  
Vol 893 ◽  
Author(s):  
Alexander Landa ◽  
Per Söderlind
Keyword(s):  
Electronic Structure ◽  
Equation Of State ◽  
Density Functional ◽  
Relativistic Effects ◽  
Model Systems ◽  
Face Centered Cubic ◽  
Electronic Structure Methods ◽  
The Face ◽  
Face Centered ◽  
Structure Calculations

AbstractThe effect of the relativistic spin-orbit (SO)interaction on the bonding in the early actinides has been investigated by means of electronic-structure calculations. Specifically, the equation of state (EOS) for the face-centered cubic (fcc) model systems of these metals has been calculated from the first-principles density-functional (DFT) theory. Traditionally, the SO interaction in electronic-structure methods is implemented as a perturbation to the Hamiltonian that is solved for basis functions that explicitly do not depend on SO coupling. Here this approximation is shown to compare well with the fully relativistic Dirac treatment. It is further shown that SO coupling has a gradually increasing effect on the EOS as one proceeds through the actinides and the effect is diminished as density increases.

Density Functional Study of N2Activation by Molybdenum(III) Complexes. Unusually Strong Relativistic Effects in 4d Metal Compounds

1997 ◽  
Vol 16 (5) ◽  
pp. 995-1000 ◽  
Author(s):  
Konstantin M. Neyman ◽  
Vladimir A. Nasluzov ◽  
Jutta Hahn ◽  
Clark R. Landis ◽  
Notker Rösch
Keyword(s):  
Density Functional ◽  
Relativistic Effects ◽  
Functional Study ◽  
Metal Compounds ◽  
Density Functional Study

FIRST PRINCIPLES STUDY OF ELECTRONIC STRUCTURE AND MAGNETIC PROPERTIES OF HALF-METALLIC FULL-HEUSLER ALLOYS Co2MnSi and Co2FeSi

2010 ◽  
Vol 24 (08) ◽  
pp. 967-978 ◽  
Author(s):  
JINGSHAN QI ◽  
HAILIN YU ◽  
XUEFAN JIANG ◽  
DANING SHI
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Energy Gap ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Lattice Parameters ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Half Metallic

We present a comprehensive investigation of the equilibrium structural, electronic and magnetic properties of C o2 MnSi and C o2 FeSi by density-functional theory (DFT) within the generalized gradient approximation (GGA) using the projected augmented wave (PAW) method. The on-site Coulomb interaction has also taken into account ( GGA +U) approach to unravel the correlation effects on the electronic structure. The change of the energy gap, "spin gap", Fermi energy level and magnetic moments with the lattice parameters is investigated. We found that the on-site correlation interaction in C o2 FeSi is stronger than in C o2 MnSi . So on-site electronic correlation is necessary for C o2 FeSi and the magnetic moments reproduce experimental results well by GGA +U. Further we also found that a moderate change of the lattice parameters does not change the half-metallic ferromagnet (HMF) behavior for both materials. Appearance of half-metallicity is consistent with the integral magnetic moments, which also agrees with the experiment measurements.

Study on First-Principles of Nano-Materials Named Manganese Oxide

2011 ◽  
Vol 110-116 ◽  
pp. 1886-1891
Author(s):  
Gui Lin Lu ◽  
Xun Lei Wu ◽  
Zi Bo Li ◽  
Ji Hai Yang
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Giant Magnetoresistance ◽  
Catalytic Properties ◽  
Lattice Structure ◽  
Relativistic Effects ◽  
Spin States ◽  
Nano Materials ◽  
Functional Theory ◽  
Theory Base

The physical properties of nano-Mn3O4 is Characterize by theory base clusters of Physical Chemistry, Including the lattice structure, catalytic properties, the phenomenon of giant magnetic and giant magnetoresistance, N dimensional wave function is approximation to be expressed as variational parameters of nonlinear multivariate function by Density Functional Theory, Extreme functional is obtained by Wavelet analysis ,And analyzed the data characteristics on relationship between Particle size, concentration, temperature, magnetic field strength of a4 , a5 and time, Compared with bulk materials, nano materials, bond angles, bond length parameters, Resolved electron spin states and relativistic effects of the problem, Correction of the uneven distribution of electron density because the error caused.

Effects of vanadium impurity on TiO2 properties

2015 ◽  
Vol 29 (15) ◽  
pp. 1550094 ◽  
Author(s):  
Arvids Stashans ◽  
Jairo Escobar
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Of States ◽  
Density Functional ◽  
Magnetic Moments ◽  
Equilibrium Geometry ◽  
Dft Studies ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Atomic Rearrangement

Our present work is based on the density functional theory (DFT) studies of TiO 2 crystals doped with V impurities. Both rutile and anatase structures have been considered within the present research and different defect concentrations have been used as well. Our calculations reveal equilibrium geometry of the system showing atomic rearrangement around the point defect being mainly inward with respect to the impurity. Magnetism and electronic structure based on the density of states (DOS) patterns for both rutile and anatase crystals have been obtained and discussed in detail. It is shown that local magnetic moments arise mainly from the 3d states of the impurity atom with some admixture of 2p states from the vanadium-nearest O atoms.

scholarly journals Electronic Structure and High Magnetic Properties of (Cr, Co)-codoped 4H–SiC Studied by First-Principle Calculations

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 634
Author(s):  
Mengyu Zhang ◽  
Jingtao Huang ◽  
Xiao Liu ◽  
Long Lin ◽  
Hualong Tao
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Density Functional ◽  
Magnetic Moments ◽  
Electronic Transitions ◽  
Electronic Density ◽  
Functional Theory ◽  
Metallic Material ◽  
Near Future ◽  
Co Doped

The electronic structure and magnetic properties of 3d transition metal (Cr, Co)-codoped 4H–SiC were studied by density functional theory within GGA methods. The results show that all doped magnetic atoms have high magnetic properties in both Cr-doped and Co-doped 4H–SiC, resulting in the net magnetic moments of 3.03, 3.02 μ B for Si 35 CrC 36 and Si 35 CoC 36 . The electronic density of states reaches the peak at Fermi level, which is beneficial to the electronic transitions, indicating that Cr-doped 4H–SiC is a semi-metallic material. In addition, the magnetic properties of (Cr, Co)-codoped 4H–SiC were also calculated. The results show that the (Cr, Co)-codoped 4H–SiC system has more stable ferromagnetic properties with ΔE F M of −244.3 meV, and we estimated T C of about 470.8 K for the (Cr, Co)-codoped 4H–SiC system. The (Cr, Co)-codoped 4H–SiC can be ferromagnetic through some mechanism based on hybridization between local Cr:3d, Co:3d and C:2p states. These interesting discoveries will help promote the use of excellent SiC-based nanomaterials in spintronics and multi-function nanodevices in the near future.

Electronic Structure and Magnetic Properties of Ga-Doped Heusler Alloy Co2FeSi

2011 ◽  
Vol 130-134 ◽  
pp. 1430-1434 ◽  
Author(s):  
Yu Feng ◽  
Bo Wu ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Doping Concentration ◽  
Magnetic Moments ◽  
Half Metallicity ◽  
Functional Theory ◽  
Half Metallic ◽  
Heusler Compound ◽  
Lattice Constants ◽  
The Density Functional Theory

Using GGA+U (UCo=2.1eV, UFe=2.5eV) scheme based on the density functional theory (DFT), we investigate the electronic structure, magnetism and half-metallic stability of Ga-doped Heusler compound Co2FeSi. We find that the lattice constants and total magnetic moments in per unit respectively obey the Vegard’s rule and the Slater-Pauling rule well. The most stable half-metallicity occurs at doping concentration x=0.5 due to the Fermi level is situated slightly above the middle of the spin-down gap. Our studies also indicate that the RKKY-type exchange mechanism plays a dominating role in determining the magnetism of HMFs.

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