ELECTRONIC STRUCTURES OF NAKED AND MOLECULAR ENCAPSULATED Au NANOPARTICLES

2009 ◽  
Vol 08 (01n02) ◽  
pp. 181-184
Author(s):  
Y. YAMASHITA ◽  
S. HE ◽  
H. YOSHIKAWA ◽  
S. UEDA ◽  
K. KOBAYASHI ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electronic Structures ◽  
Au Nanoparticles ◽  
Present System ◽  
Valence States ◽  
Densities Of States ◽  
Encapsulated Nanoparticles

Naked and molecular encapsulated Au nanoparticles with a diameter of 3 nm were prepared on top of Si in order to elucidate the effect of the molecules on the electronic structures of Au nanoparticles. We have found that the naked particles showed the finite densities of states at the Fermi level while the molecular encapsulated particles exhibited the edge being away from the Fermi level, indicating that the naked and molecular encapsulated Au particles should show metallic and nonmetallic features, respectively. Furthermore, because the naked Au nanoparticles became nonmetallic upon the particles adsorbing the molecules, the highly occupied states of the molecules might be hybridized with the valence states of Au particles, resulting in nonmetallic properties of the molecular encapsulated nanoparticles in the present system.

Photoemission Study of Thiol-Capped Gold Nanoparticles

2001 ◽  
Vol 704 ◽  
Author(s):  
Tazumi Nagasawa ◽  
Akinori Tanaka ◽  
Hiroyuki Sasaki ◽  
Yosuke Kuriyama ◽  
Shoji Suzuki ◽  
...  
Keyword(s):  
Fermi Level ◽  
Electronic Structures ◽  
Metallic Nanoparticles ◽  
Au Nanoparticles ◽  
Pyrolytic Graphite ◽  
Leading Edge ◽  
Steep Slope ◽  
Substrate Interaction ◽  
Fermi Edge ◽  
Photoemission Study

AbstractA photoemission study of dodecanethiol (DT)-capped Au nanoparticles on the highly oriented pyrolytic graphite (HOPG) substrates has been carried out in order to investigate in detail the electronic structures of metallic nanoparticles supported on the substrates. The present DT-capped Au nanoparticles show that the leading edge in the photoemission spectra near the Fermi level is not the Fermi edge, with the midpoint of the steep slope being away from the Fermi level. From these results, we discuss the electronic structures of DT-capped Au nanoparticles, especially nanoparticle-HOPG substrate interaction.

The chemical potential for a semiconductor

2021 ◽  
pp. 336-345
Author(s):  
Geoffrey Brooker
Keyword(s):  
Fermi Level ◽  
Chemical Potential ◽  
Electron Hole ◽  
Densities Of States ◽  
The Way

“The chemical potential for a semiconductor” deals with the way in which the chemical potential (Fermi level) of a semiconductor is affected: by the densities of states in the bands; by temperature; and by doping. The electron–hole product is usually independent of doping but sensitive to temperature. The chemical potential is worked out numerically for an example case, and is shown to be most sensitive to doping.

First-principle study of the structural, mechanical, electronic and thermodynamic properties of intermetallic compounds: Pd3M (M=Sc, Y)

2019 ◽  
Vol 33 (27) ◽  
pp. 1950321
Author(s):  
R. Boulechfar ◽  
A. Trad Khodja ◽  
Y. Khenioui ◽  
H. Meradji ◽  
S. Drablia ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Fermi Level ◽  
Debye Model ◽  
Pressure Effects ◽  
Full Potential ◽  
Generalized Gradient ◽  
Text Structures ◽  
Formation Enthalpies ◽  
Densities Of States ◽  
Experimental Findings

The mechanical, electronic and thermodynamic properties of Pd3M (M[Formula: see text]=[Formula: see text]Sc, Y) compounds have been investigated using the Full Potential Linearized Augmented Plane Wave (FP-LAPW) formalism. The generalized gradient approximation (GGA) is used to treat the exchange–correlation terms. The calculated formation enthalpies and the cohesive energies reveal that the L12 structure is more stable than the D0[Formula: see text] one. The obtained lattice parameters and bulk modulus calculations conform well to the available experimental and theoretical results. The elastic and mechanical properties are analyzed and results show that both compounds are ductile in nature. The Debye temperature and melting temperature are also estimated and are in a good agreement with experimental findings. The total and partial densities of states are determined for L12 and D0[Formula: see text] structures. The density of states at the Fermi level, [Formula: see text]([Formula: see text]), indicates electronic stability for both compounds. The presence of the pseudo-gap near the Fermi level is suggestive of formation of directional covalent bonding. The number of bonding electrons per atom [Formula: see text] and the electronic specific heat coefficient [Formula: see text] are also determined. The quasi-harmonic Debye model has been used to explore the temperature and pressure effects on the thermodynamic properties for both compounds.

Valence States of Transition-Metal Ions and Electronic Structures of Spinel Fe$_{1-x}$Cu$_x$Cr$_2$S$_4$

2007 ◽  
Vol 43 (6) ◽  
pp. 3046-3048 ◽  
Author(s):  
J.-S. Kang ◽  
S. W. Han ◽  
S. S. Lee ◽  
G. Kim ◽  
C. Hwang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Electronic Structures ◽  
Transition Metal Ions ◽  
Valence States

The Characteristics of Chemisorptions on Si (001) Surface

2015 ◽  
Vol 723 ◽  
pp. 972-975
Author(s):  
Ying Tang Zhang ◽  
Jun Fang Wu
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Energy Curve ◽  
Densities Of States

The characteristics of chemisorptions, such as the pseudogap, forbidden bandwidth, energy curve, the trend of Fermi level in the graphics and the density of states at the Fermi level and so on, were given for the chemisorptions of atom on the Si (001) surface from the density of states. From these densities of states’ curves, the characteristics of chemisorptions were analyzed and compared to for different elements absorption on the Si (001) surface. The density of states for chemisorptions is different for the different elements.

The thermopower of transition-metal double-perovskites: A sensitive probe of their electronic structures around the Fermi level

2007 ◽  
Vol 7 (2) ◽  
pp. 151-155 ◽  
Author(s):  
B. Fisher ◽  
J. Genossar ◽  
K.B. Chashka ◽  
L. Patlagan ◽  
G.M. Reisner
Keyword(s):  
Transition Metal ◽  
Fermi Level ◽  
Electronic Structures ◽  
Double Perovskites

Investigation on field-emission properties of graphdiyne–ZnO composite

2018 ◽  
Vol 32 (24) ◽  
pp. 1850285 ◽  
Author(s):  
Xiaoming Yuan ◽  
Yanqi Yang ◽  
Juan Guo ◽  
Daohan Ge ◽  
Ping Yang
Keyword(s):  
Binding Energy ◽  
Electric Field ◽  
Fermi Level ◽  
Field Emission ◽  
Electronic Structures ◽  
Composite Model ◽  
High Binding Energy ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Work Functions

Graphdiyne–ZnO composite is constructed to investigate field-emission. We hope the tip effect of graphdiyne can be strengthened by doping ZnO. We find that the effective movement of the Fermi level and the dwindling of band gap have contributed to the modification of the electronic structures of this composite significantly with increase in the electric field. The high binding energy indicates that the composite model is very stable. In addition, the ionization energies and work functions decrease linearly with the increasing electric field, which represents an improvement of field-emission properties. It implies that graphdiyne–ZnO composite may become a promising material for field-emission.

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