CALCULATION FOR A Cu(001) SURFACE WITH AN IMPURITY ATOM

1999 ◽  
Vol 13 (04) ◽  
pp. 389-396
Author(s):  
CHIH-KAI YANG
Keyword(s):  
Electronic Structure ◽  
Impurity Atom ◽  
Magnetic Moments ◽  
Tight Binding ◽  
Real Space ◽  
Structure Calculation ◽  
Spin Polarized ◽  
Densities Of States ◽  
Self Consistent ◽  
Local Densities

I use a self-consistent electronic structure calculation to study the system of Cu(001) that has an impurity atom replacing one of the surface Cu atoms. The calculation makes use of the tight-binding linear muffin-tin orbitals (TB-LMTO) and is carried out in real space. I am able to derive the spin-polarized local densities of states for the impurity Cr and Fe respectively, which have peaks below the Fermi level. Charge transfers between the impurities and their neighbors also result in different distributions of magnetic moments for the two impurity systems, with the Cr having approximately 0.5μ B and the Fe atom having a negligible magnetic moment.

Electronic Structure of Ordered and Disordered Ternary Intermetallics

1992 ◽  
Vol 291 ◽  
Author(s):  
C. Wolverton ◽  
D. De Fontaine
Keyword(s):  
Electronic Structure ◽  
Tight Binding ◽  
Real Space ◽  
Orbital Method ◽  
Densities Of States ◽  
Effective Pair ◽  
Ternary Additions ◽  
Self Consistency ◽  
Structure Calculations ◽  
Space Method

ABSTRACTA cluster expansion for energetics is combined with a direct, real-space method of studying the electronic structure of ordered and disordered ternary intermetallics. The electronic structure calculations are based on an explicit averaging of local quantities over a small number of randomly chosen configurations. Quantities such as densities of states, one-electron energies, etc., are computed within the framework of the first-principles tight-binding linear muffin-tin orbital method (TB-LMTO). Effective pair interactions, which describe the ordering tendencies of the alloy, are computed for the full ternary alloy. With this technique, then, the effects on ordering trends of ternary additions to a binary alloy may be obtained. Results for Ag-Pd-Rh and Ni-Al-Cu are shown. The self-consistency of these calculations is checked against the fully self-consistent ordered LMTO calculations.

scholarly journals The Electronic Structure of Grain Boundaries in NB

1990 ◽  
Vol 209 ◽  
Author(s):  
Erik C. Sowa ◽  
A. Gonis ◽  
X. -G. Zhang
Keyword(s):  
Electronic Structure ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Multiple Scattering ◽  
First Principles ◽  
Scattering Theory ◽  
Real Space ◽  
First Principles Calculations ◽  
Densities Of States ◽  
Local Densities

ABSTRACTWe present first-principles calculations of the electronic structure of Nb grain boundaries. These are the first such calculations for a bcc metal using the real-space multiple-scattering theory (RSMST). Local densities of states near a Σ5 twist grain boundary are compared to those for bulk Nb.

Stepped Fe(100) and V/Fe(100) Magnetism

1991 ◽  
Vol 231 ◽  
Author(s):  
A. Vega ◽  
A. Rubio ◽  
L.C. Balbas ◽  
J. Dorantes-Davila ◽  
C. Demangeat ◽  
...  
Keyword(s):  
Transition Metal ◽  
Flat Surface ◽  
Magnetic Moments ◽  
Tight Binding ◽  
Step Length ◽  
Real Space ◽  
External Edge ◽  
Transition Metal Surface ◽  
Self Consistent ◽  
Stepped Surface

AbstractWe have investigated the magnetic arrangment of 3d transition-metal stepped surface by using a self-consistent real-space tight-binding method. As expected, the presence of steps modifies locally the properties of a transition-metal surface. We emphasized the influence of atomic environment. We found for the (100)-Fe surface, an enhancement of the magnetic moments of the external edge of this step as compared to the flat surface. The results are not very sensitives to the step length. More striking is the case of the (100)-V stepped surface where atoms at the external edge display a large magnetic moment.

The Electronic Structure pf Σ5 Grain Boundaries in CU

1989 ◽  
Vol 159 ◽  
Author(s):  
Erik C. Sowa ◽  
A. Gonis ◽  
X.-G. Zhang
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
First Principles ◽  
Real Space ◽  
Embedded Atom Method ◽  
First Principles Calculations ◽  
Bulk Materials ◽  
Embedded Atom ◽  
Densities Of States ◽  
Self Consistent

ABSTRACTWe present first-principles calculations of the densities of states (DOS's) of unrelaxed and relaxed twist and tilt grain boundaries (GB's) in Cu. The relaxed configurations were obtained through the use of the Embedded Atom Method (EAM), while the DOS's were calculated using the real-space multiplescattering theory (RSMST) approach recently introduced in the literature. The DOS's of GB's are compared against those of bulk materials as well as against one another. Although the RSMST calculations are still not self-consistent, these comparisons allow us to verify certain expected trends in the DOS's, and to verify the usefulness and reliability of our method.

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.

Electronic Structure of Epitaxial SiO2/Si(100) Interfaces

1989 ◽  
Vol 159 ◽  
Author(s):  
T. Motooka
Keyword(s):  
Tight Binding ◽  
Interface States ◽  
Photoelectron Spectra ◽  
Band Spectrum ◽  
Binding Model ◽  
Initial Oxidation ◽  
Recursion Method ◽  
Densities Of States ◽  
Local Densities ◽  
Gap States

ABSTRACTThe local densities of states (LDOS) of epitaxial SiO, layers on Si(100) surfaces have been calculated using the recursion method combined with the Harrison's universal tight-binding model. The interface states associated with strained epitaxial layers of β-cristobalite (√2×√2)R45° and tridymite (1010)<0001> || Si(100)<011> were examined. In the β-cristobalite layer, gap states due to the surface Si dangling bonds appeared while they were eliminated by H termination. In the tridymite layer, the interface states primarily composed of the surface Si back bonds appeared near the Si conduction band minimum. Comparing the calculated DOS with photoelectron spectra for initial oxidation processes of clean Si(100), it was found that the valence band spectrum from the initial oxide formed at ∼300°C resembled that of the β-cristobalite layer.

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