scholarly journals Quasi-non-uniform gradient-level exchange-correlation approximation for metals and alloys

2012 ◽  
Vol 86 (20) ◽  
Author(s):  
H. Levämäki ◽  
M. P. J. Punkkinen ◽  
K. Kokko ◽  
L. Vitos
Keyword(s):  
Metals And Alloys ◽  
Exchange Correlation ◽  
Correlation Approximation

scholarly journals Flexibility of the quasi-non-uniform exchange-correlation approximation

2014 ◽  
Vol 89 (11) ◽  
Author(s):  
H. Levämäki ◽  
M. P. J. Punkkinen ◽  
K. Kokko ◽  
L. Vitos
Keyword(s):  
Exchange Correlation ◽  
Correlation Approximation

scholarly journals Energy spectrum and density of states in 3d-transient metals and alloys

2020 ◽  
pp. 102-111
Author(s):  
F.G. Kizhaev ◽  
◽  
N.N. Medvedev ◽  
O.V. Starygina ◽  
◽  
...  
Keyword(s):  
Electronic Structure ◽  
Energy Spectrum ◽  
Transition Metals ◽  
Density Of States ◽  
Magnetic Moment ◽  
Metals And Alloys ◽  
Peak Density ◽  
Exchange Correlation ◽  
Transient Metals ◽  
D Model

In this paper, the formation of the magnetic moment, the energy spectrum and the density of States of d -electrons in transition metals are considered in the framework of a two-zone s - d model based on a generalized crystalline Hamiltonian. It is shown that taking into account the multiplicity of the degeneration of s - d electrons in the Hamiltonian leads to an additional exchange-correlation interaction ( U - K ), which together with the correlation interaction determines the electronic structure of d -metals. In this case, there is a three-peak density of States, which turns into a two-peak, if we exclude the exchange-correlation interaction.

A DFT Study of Electronic and Magnetic Properties of Cr2O3 using Spin-Polarized Approach

2018 ◽  
Vol 1 (1) ◽  
pp. 91-96
Author(s):  
Abeer E. Aly ◽  
D. P. Rai
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Electronic And Magnetic Properties ◽  
The Density Functional Theory ◽  
Spin Polarized ◽  
Correlation Approximation

The study of Cr2O3 magneto-electric material, particularly, the profound understanding of its antiferro-magnetic, is vital for its spintronics applications. In this paper, we present a study on electronic and magnetic properties of Cr2O3 crystal using the first-principles calculations based on the density functional theory. For more accurate results, additional Hubbard (U) parameter has been employed to GGA as well. Our calculated results are homogeneous with available experimental measurements. Results show the effects produced by GGA+U method upon the electronic and magnetic features of the material. We prove that, the spherically symmetric GGA+U approach for exchange correlation approximation portray is a superior depiction of electronic and magnetic properties of Cr2O3.

Some Applications of the U. S. Steel MVEM

1973 ◽  
Vol 31 ◽  
pp. 4-5
Author(s):  
J. S. Lally ◽  
L. E. Thomas ◽  
R. M. Fisher
Keyword(s):  
Electron Diffraction ◽  
Debye Temperature ◽  
Metals And Alloys ◽  
Critical Voltage ◽  
Dynamical Diffraction ◽  
Phase Structures ◽  
Structure Factors ◽  
Local Bonding ◽  
Diffraction Phenomenon ◽  
Multi Phase

A variety of materials containing many different microstructures have been examined with the USS MVEM. Three topics have been selected to illustrate some of the more recent studies of diffraction phenomena and defect, grain and multi-phase structures of metals and minerals.(1) Critical Voltage Effects in Metals and Alloys - This many-beam dynamical diffraction phenomenon, in which some Bragg resonances vanish at certain accelerating voltages, Vc, depends sensitively on the spacing of diffracting planes, Debye temperature θD and structure factors. Vc values can be measured to ± 0.5% in the HVEM ana used to obtain improved extinction distances and θD values appropriate to electron diffraction, as well as to probe local bonding effects and composition variations in alloys.

Inelastic scattering at surfaces and interfaces

1986 ◽  
Vol 44 ◽  
pp. 392-393
Author(s):  
R. H. Ritchie ◽  
A. Howie
Keyword(s):  
Inelastic Scattering ◽  
Surface Properties ◽  
Correlation Energy ◽  
Condensed Matter ◽  
Charged Particles ◽  
Condensed Matter Physics ◽  
Optical Phonons ◽  
Exchange Correlation ◽  
Surfaces And Interfaces ◽  
Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

Sign in / Sign up

Export Citation Format

Share Document