A LEED Fine Structure Study of Oxygen Adsorption on Cu(001) and Cu(111)

1990 ◽  
Vol 43 (5) ◽  
pp. 519 ◽  
Author(s):  
C Hitchen ◽  
S Thurgate ◽  
P Jennings
Keyword(s):  
Fine Structure ◽  
Long Range ◽  
Potential Barrier ◽  
Incident Beam ◽  
Oxygen Adsorption ◽  
Structure Study ◽  
Threshold Effects ◽  
Range Image ◽  
Adsorption Sites ◽  
Barrier Potential

LEED fine structure features are due to an interference between the measured beam (usually the specular) and a pre-emergent beam. This pre-emergent beam is internally reflected at the surface potential barrier and is subsequently diffracted by the substrate into the same direction as the beam under observation. As a result of the long-range image nature of the barrier potential, a rydberg-like series of peaks, converging on the emergence energy of the pre-emergent beam, is produced. Fine structure features, or threshold effects, occur at very low incident beam energies (typically <40 eV) and are extremely sensitive to the surface order of the crystal. The changes that occur to the fine structure features when atoms are adsorbed onto the surface contain information regarding the nature of the chemisorption process. In some cases it is possible to infer adsorption sites. In this work measurements are made of the fine structure features for the (001) and (111) surfaces of copper as a function of oxygen exposure. Analysis of these data shows that oxygen adsorption on (u(111) takes place in a disordered manner and results in a roughening of the surface, while for (u(OOl) the adsorption produces an ordered overlayer with oxygen atoms in the 2-fold bridge sites.

Structure study of the chalcogens and chalcogenides by X-ray absorption fine structure

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroyuki Ikemoto ◽  
Takafumi Miyanaga
Keyword(s):  
Fine Structure ◽  
Covalent Bond ◽  
Narrow Channel ◽  
Structure Study ◽  
Chain Structure ◽  
Covalent Bonds ◽  
X Ray ◽  
Absorption Fine ◽  
Amorphous States ◽  
X Ray Absorption

AbstractIn this review, we make a survey of the structure studies for the chalcogen elements and several chalcogenides in liquid, amorphous and nanosized state by using X-ray absorption fine structure (XAFS). The chalcogen elements have hierarchic structures; the chain structure constructed with the strong covalent bond as a primary structure, and the weaker interaction between chains as a secondary one. Existence of these two kinds of interactions induces exotic behaviors in the liquid, amorphous and nanosized state of the chalcogen and chalcogenides. XAFS is a powerful structure analysis technique for multi-element systems and the disordered materials, so it is suitable for the study of such as liquid, amorphous and nanosized mixtures. In section 2, the structures for the liquid state are discussed, which show the interesting semiconductor-metal transition depending on their temperatures and components. In section 3, the structure for the amorphous states are discussed. Especially, some of chalcogens and chalcogenides present the photostructural change, which is important industrial application. In section 4, the structures of nanosized state, nanoparticles and isolated chain confined into the narrow channel, are discussed. The studies of the nanoparticle and the isolated chain reveal the alternative role between the intrachain covalent bonds and the interchain interaction.

Extended x-ray-absorption fine-structure study of Ag particles isolated in solid argon

1984 ◽  
Vol 30 (2) ◽  
pp. 672-677 ◽  
Author(s):  
P. A. Montano ◽  
W. Schulze ◽  
B. Tesche ◽  
G. K. Shenoy ◽  
T. I. Morrison
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
Ag Particles ◽  
Solid Argon ◽  
X Ray Absorption

X-ray absorption fine structure study of Cr 2 O 3-x

1995 ◽  
Author(s):  
I. Pop ◽  
O. Pop ◽  
Ioan Burda ◽  
C. Oprea ◽  
I. Nazarenco ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

X-ray-absorption fine structure study on devitrification of ultrafine amorphous Ni-B alloys

2001 ◽  
Vol 63 (22) ◽  
Author(s):  
Shiqiang Wei ◽  
Hiroyuki Oyanagi ◽  
Zhongrui Li ◽  
Xinyi Zhang ◽  
Wenhan Liu ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption

X-Ray Absorption Fine Structure Study in FeTiO3

1997 ◽  
Vol 11 (16n17) ◽  
pp. 745-748 ◽  
Author(s):  
Rebekah Min-Fang Hsu ◽  
Kai-Jan Lin ◽  
Cheng Tien ◽  
Lin-Yan Jang
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Mixed Valence ◽  
Structure Study ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Trivalent State ◽  
X Ray Absorption

X-ray absorption fine structure XAFS spectroscopy has been used to determine the valence system for the Fe atom in ilmenite, FeTiO3 . This is the first XAFS data in FeTiO3 to our knowledge. The α- Fe2O3 data served as the standard in determining the ionization of the Fe atom in FeTiO3 . Observation of intensity and k-space are consistent. There was no evidence of mixed valence on comparing the FeTiO3 near edge X-ray absorption spectrum with α- Fe2O3 data. The absorption spectra suggest that iron is in the trivalent state in ilmenite.

scholarly journals SURFACE EXTENDED X-RAY ABSORPTION FINE STRUCTURE STUDY ON (2x1) OXYGEN ON Ni(110)

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-473-C8-478 ◽  
Author(s):  
U. DÖBLER ◽  
L. WENZEL ◽  
D. ARVANITIS ◽  
K. BABERSCHKE
Keyword(s):  
Fine Structure ◽  
Structure Study ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption
Sign in / Sign up

Export Citation Format

Share Document