Optical Absorption in a Model Transition Metal Including Correlation

1974 ◽  
Author(s):  
J. C. Shaffer ◽  
A. J. Fedro
Keyword(s):  
Transition Metal ◽  
Optical Absorption ◽  
Model Transition

scholarly journals OPTICAL ABSORPTION AND EPR STUDY OF TRANSITION METAL IONS DOPED PHOSPHATE GLASSES

1996 ◽  
Vol 6 (0) ◽  
pp. 241-244 ◽  
Author(s):  
MOHAMED HAOUARI ◽  
HAFEDH BEN OUADA ◽  
HASSEN MAAREF ◽  
HUBERT HOMMEL ◽  
ANDRE PIERRE LEGRAND
Keyword(s):  
Transition Metal ◽  
Optical Absorption ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Phosphate Glasses

scholarly journals The Effect of Iron Impurities on Transition Metal Catalysts for the Oxygen Evolution Reaction in Alkaline Environment: Activity Mediators or Active Sites?

2020 ◽  
Author(s):  
Ioannis Spanos ◽  
Justus Masa ◽  
Aleksandar Zeradjanin ◽  
Robert Schlögl
Keyword(s):  
Transition Metal ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Alkaline Water Electrolysis ◽  
Co Catalysts ◽  
Model Transition

AbstractThere is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stability. Graphic Abstract

Mechanisms for hydrogen evolution on transition metal phosphide catalysts and a comparison to Pt(111)

2019 ◽  
Vol 21 (44) ◽  
pp. 24489-24498 ◽  
Author(s):  
Chenyang Li ◽  
Hao Gao ◽  
Wan Wan ◽  
Tim Mueller
Keyword(s):  
Monte Carlo ◽  
Transition Metal ◽  
Monte Carlo Simulations ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Surface Coverage ◽  
Cluster Expansions ◽  
Metal Phosphide ◽  
Transition Metal Phosphide ◽  
Model Transition

Cluster expansions and Monte Carlo simulations provide insights into the mechanisms for the hydrogen evolution reaction and the effects of potential and surface coverage on Pt(111) and model transition metal phosphide surfaces.

Chemisorption of Ordered Overlayer on a Tight-Binding Metal Surface Two-Level Adsorbate

1982 ◽  
Vol 37 (10) ◽  
pp. 1147-1164
Author(s):  
K. Masuda
Keyword(s):  
Phase Shift ◽  
Transition Metal ◽  
Density Of States ◽  
Tight Binding ◽  
Electronic States ◽  
Bridge Site ◽  
Bonding Interaction ◽  
Model Transition ◽  
Adsorbate Structure ◽  
Shift Technique

The chemisorption of a two-level (at E1 and E2) adsorbate on the (001) surface of a tightbinding metal is investigated using the Green's function formalism and the phase shift technique. The adorbital density of states (DOS)ϱa(E) as well as the change in the electronic DOS Δϱ(E; E1, E2) due to chemisorption are calculated for the ordered overlayers with c(2 x 2), p(2 x 1), p(2 X 2), p(4 X 1) and c(4 X 2) structures. It is assumed that the chemisorbed species sit over the twofold bridge site of the (001) surface of the model transition metal and have a π-bonding interaction with the two substrate atoms. It is shown that the electronic states of the overlayers are very sensitive to the adsorbate coverage (0), adsorbate structure and adsorbate species (one level or two level adsorbates). Furthermore, it is shown that there are marked differences in the Δϱ(E) curves between the chemisorption of two level adsorbates Δϱ(E; E1, E2) and that of single level adsorbates Δϱ(E; E1) + Δϱ(E; E2) (simulating the changes in the electronic DOS during the dissociation of diatomic molecules).

The crystal chemistry of (Mn3 +, Fe3+)-substituted andalusites (viridines and kanonaite), (Al1−x−yMn3x+Fe3y+)2 (OǀSiO4): crystal structure refinements, Mössbauer, and polarized optical absorption spectra

1981 ◽  
Vol 155 (1-2) ◽  
Author(s):  
I. Abs-Wurmbach ◽  
K. Langer ◽  
F. Seifert ◽  
E. Tillmanns
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Optical Absorption ◽  
Metal Ions ◽  
Crystal Chemistry ◽  
Mixed Crystal ◽  
Transition Metal Ions ◽  
Structure Type ◽  
Optical Absorption Spectra ◽  
Distorted Octahedral

AbstractThe crystal chemistry of viridines and kanonaite, (AlThe structure refinements reveal that the transition metal ions substitute for Al almost exclusively in the distorted octahedral Al(l) site of the andalusite structure type within the entire mixed crystal series. This is independently proven by the Mössbauer results for

Changes in Density of States Caused by Chemisorption: Monolayer of Adatoms on a Model Transition Metal

1978 ◽  
Vol 33 (1) ◽  
pp. 66-73
Author(s):  
Kin-ichi Masuda
Keyword(s):  
Electronic Structure ◽  
Phase Shift ◽  
Transition Metal ◽  
Density Of States ◽  
Anderson Model ◽  
Surface Density ◽  
Direct Interaction ◽  
Coverage Dependence ◽  
Model Transition ◽  
Shift Technique

The effect of chemisorption of a monolayer of atoms on the (001) surface of a model transition metal is investigated using the Green's function formalism and the phase shift technique. The electronic structure of the surface is obtained by the application of the Kalkstein and Soven method. For comparison, both a single and two peaked model of the surface density of states (DOS) are used. The change in the DOS upon chemisorption as well as the adatom DOS are calculated within the Newns-Anderson model for chemisorption. It is shown that the two peaked substrate DOS model can qualitatively account for the strong coverage dependence of the photoemission spectra observed in the H/W(100) system. In addition, it is shown that the direct interaction between the adatoms plays an important role in the monolayer chemisorption.

Sign in / Sign up

Export Citation Format

Share Document