Spectroscopic Investigations of Dendrimer-Au Hybrid Nanoclusters

2007 ◽  
Vol 1056 ◽  
Author(s):  
Akinori Tanaka ◽  
Yoshiaki Murase ◽  
Takanobu Kitagawa ◽  
Masaki Imamura ◽  
Hidehiro Yasuda
Keyword(s):  
Electronic Structures ◽  
Spectral Feature ◽  
Spectroscopic Studies ◽  
Core Level ◽  
Photoemission Spectrum ◽  
Au Nanoclusters ◽  
Final State ◽  
X Ray ◽  
Mean Diameter ◽  
Shape Analyses

ABSTRACTWe have synthesized the dendrimer-Au hybrid nanoclusters by solution routes, and have carried out the various spectroscopic studies in order to investigate their electronic structures. From the line-shape analyses for Au 4f core-level photoemission spectra measured with hard X-ray synchrotron-radiation of Au nanoclusters with mean diameter of 2-3 nm stabilized outside the dendrimer, it is found that Au 4f core-level photoemission spectrum consists of two components. We attribute these components to interior Au atoms and surface Au atoms bonded to dendrimers. In the valence-band photoemission spectrum of these Au nanoclusters, we have observed the bandwidth narrowing of Au 5d-derived band compared to that of bulk Au crystallite. Moreover, we have observed the characteristic spectral feature in the vicinity of Fermi level due to the dynamic final-state effect in photoemission. We have also carried out the optical spectroscopic measurements of these Au nanoclusters. From these results, we discuss the electronic structures and interfacial properties of the dendrimer-Au hybrid nanoclusters.

scholarly journals Effect of electron correlation in the decomposition of core level binding energy shifts into initial and final state contributions

2019 ◽  
Vol 21 (18) ◽  
pp. 9399-9406 ◽  
Author(s):  
Marc Figueras ◽  
Carmen Sousa ◽  
Francesc Illas
Keyword(s):  
Binding Energy ◽  
Electron Correlation ◽  
Photoelectron Spectroscopy ◽  
Core Level ◽  
Final State ◽  
X Ray ◽  
Core Level Binding Energy

The influence of electron correlation into the decomposition of core level binding energy shifts, measured by X-ray photoelectron spectroscopy (XPS), into initial and final effects is analysed for a series of molecules where these effects are noticeable.

X-Ray Photoelectron Spectroscopic Studies of Palladium Dispersed on Carbon Surfaces Modified by Ion Beams and Plasmatic Oxidation

1995 ◽  
Vol 60 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Zdeněk Bastl
Keyword(s):  
Binding Energy ◽  
Photoelectron Spectroscopy ◽  
Surface Coverage ◽  
Spectroscopic Studies ◽  
Core Level ◽  
Graphite Surface ◽  
Photoelectron Spectra ◽  
Surface Layers ◽  
X Ray ◽  
Core Level Binding Energy

The effects of ion bombardment and r.f. plasma oxidation of graphite surfaces on subsequent growth and electronic properties of vacuum deposited palladium clusters have been investigated by methods of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy with X-ray excitation (XAES). Due to the significantly increased density of surface defects on which the nucleation process occurs the bulk value of the Pd 3d core level binding energy is achieved at higher surface coverage by palladium on bombarded surfaces than on ordered graphite. Angle resolved photoelectron spectra of oxidized graphite surfaces reveal significant embedding of oxygen in graphite surface layers. The C 1s and O 1s photoelectron spectra are consistent with presence of two major oxygen species involving C-O and C=O type linkages which are not homogeneously distributed within the graphite surface layers. Two effects were observed on oxidized surfaces: an increase of palladium dispersion and interaction of the metal clusters with surface oxygen groups. Using the simple interpretation of the modified Auger parameter the relaxation and chemical shift contributions to the measured Pd core level shifts are estimated. In the region of low surface coverage by palladium the effect of palladium-oxygen interaction on Pd core level binding energy exceeds the effects of increased dispersity.

Society Photoemission and Photoabsorption Study of YNi2−xCoxB2C Superconductors

2001 ◽  
Vol 678 ◽  
Author(s):  
L.-S. Hsu ◽  
G. Y. Guo ◽  
C.-J. Chen ◽  
M.-D. Lan ◽  
J.-F. Lee
Keyword(s):  
Fine Structure ◽  
Electronic Structures ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Photoemission Spectrum ◽  
Partial Density ◽  
Superconducting Transition ◽  
X Ray ◽  
X Ray Absorption ◽  
Exafs Spectra

AbstractThe electronic structures of five polycrystalline YNi2−xCoxB2C (x=0, 0.05, 0.1, 0.15, and 0.2) borocarbide superconductors were studied by photoemission and photoabsorption spectroscopies and theoretical calculations. The valence-band (VB) photoemission spectrum is compared with the theoretical total and partial density-of-states (DOS) curves. The VB satellite is peaked at a binding energy (EB) of 6 eV. The Ni K-edge x-ray absorption near edge spectra (XANES) are compared with the calculated XANES spectra for these intermetallic compounds. Extended x-ray absorption fine structure (EXAFS) spectra at the Ni and Co K edges are analyzed to yield the structural parameters. The decrease of the superconducting transition temperatures (Tc) with addition of Co dopant in these compounds is due to a decrease of the total DOS at the Fermi level (EF).

scholarly journals Competition between initial- and final-state effects in valence- and core-level x-ray photoemission of Sb-dopedSnO2

1999 ◽  
Vol 59 (3) ◽  
pp. 1792-1799 ◽  
Author(s):  
R. G. Egdell ◽  
J. Rebane ◽  
T. J. Walker ◽  
D. S. L. Law
Keyword(s):  
Core Level ◽  
Final State ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document