X-ray photoemission studies

McFeely F R, Morar J F and Himpsel F J 1986 Soft x-ray photoemission study of the silicon-fluorine etching reaction Surf. Sc/. 165 277-87... 

As a rule in X-ray photoemission studies, more effort has been expended on the conduction bands of a metal and its alloys than on its core levels. Because the Fermi level of course lies in the bands, band level energies have not so much been the object of investigation as band structure has been and it is considered that... 

Synchrotron-radiation and x-ray photoemission studies of the valence states of condensed phase-pure Cm showed seventeen distinct molecular features extending 23 cV below the highest occupied molecular states with intensity variations due to matrix-element effects involving both cluster and free-electron-like final states. Pseudopotential calculations established the origin of these features, and comparison with experiment was excellent. The sharp C Is main line indicated a single species, and the nine satellite structures were due to shakeup and plasmon features. The 1.9-eV feature reflected transitions to the lowest unoccupied molecular level of the excited state. 

In our x-ray photoemission studies, a monochromatized photon beam (A1 Ka, hv = 1486.6 eV) was focused onto the sample surface, and the emitted electrons were energy analyzed with a Surface Sciences Instruments hemispherical analyzer. The take-off angle of the photoelectrons relative to the surface normal was 60° unless otherwise specified. A position-sensitive detector with 128 channels was used with a dedicated HP9836C computer to facilitate data acquisition. (22.) ... 

Liu P, Kendelewicz T, Brown GE Jr (1998b) Reaction of water with MgO (100) surfaces II. Synchrotron X-ray photoemission spectroscopy studies of defective surfaces. Surf Sci 412/413 315-332 Liu P, Kendelewicz T, Brown GE Jr, Parks GA, Pianetta P (1998c) Reaction of water with vacuum-cleaved CaO(lOO) surfaces An X-ray photoemission spectroscopy study. Surf Sci 416 326-340 Liu P, Kendelewicz T, Brown GE Jr, Nelson EJ, Chambers SA (1998d) Reaction of water with a-Al203 and a-Fe203 (0001) surfaces synchrotron X-ray photoemission studies and thermodynamic calculations. Surf Sci 417 53-65... 

J.M. Burkstrand, Metal-polymer interfaces adhesion and x-ray photoemission studies. 

All of the models considered so far are based on the promotional idea. However, there are some experimental results which appear to conflict with this idea. One of these is the placement of the 4f level in -y-cerium at 0.9 eV below the Fermi level by X-ray photoemission studies (see section 4.9). If these results are correct then about 20 kcal/mole of energy would be required to lift the f level to the Fermi energy to allow transfer of electrons to the conduction band. The elastic work necessary to compress a y-Ce sample to a-Ce at room temperature is two orders of magnitude smaller. This comparison is obviously an oversimplification but it serves to emphasize the importance of the proximity of the f level to the Fermi level in any promotional theory. Also, as noted in section 4.9, a 4f level could lie 0.1 eV below the Fermi level but it would not be detected by the X-ray photoemission studies. 

Liu P, Kendelewicz T, Brown GE, Nelson EJ, Chambers SA (1998) Reaction of water vapor with a-Al203 (0001) and a-Fc203 (0001) surfaces Synchrotron x-ray photoemission studies and thermodynamic... 

Early ultraviolet photoemission (Helms and Spicer 1972) and X-ray photoemission studies (Baer and Busch 1973, 1974, Poliak et al. 1976, Steiner et al. 1977, Baer and Ziircher, 1977, Crecelius et al. 1978) of metallic y-cerium showed the difficulty of separating the 4f contribution from that of the 5d and 6s electrons... 

J.M. Burkstrand, Metal-Polymer interfaces Adhesion and X-ray photoemission studies, J. Appl. Phys. 52 (1981) 4795. 

Storage, nuclear waste, x-ray photoemission spectroscopic study of actinides in silicate-based... 

K. Sugiyama, H. Ishii, Y. Ouchi, and K. Seki, Dependence of indium-tin-oxide work function on surface cleaning method as studied by ultraviolet and x-ray photoemission spectroscopies, J. Appl. 

We next discuss x-ray absorption studies. To put matters in context, it is useful to understand that conventional studies using Auger electron spectroscopy (AES) and x-ray photoemission spectroscopy (XPS) can be carried out only ex situ in high vacuum after electrochemical treatment since the techniques involve electron detection. X-ray absorption spectroscopy can, in contrast, be used for valence and structural environment studies. As x-rays only are involved, they can be carried out in situ in an electrochemical or similar cell. 

Adsorption and oxidation of NO adlayers on Pt(lll) was studied by using in situ surface X-ray diffraction and ex situ X-ray photoemission spectroscopy [86]. Molecular adsorption of NO was observed independently of the preparation of the adlayer. 

X-Ray Photoemission Spectroscopy (XPS) Study of Uranium, Neptunium, and Plutonium Oxides in Silicate-Based Glasses... 

We briefly describe here the results obtained from studies of copper, nickel and chromium overlayers deposited on polystyrene, polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, polyvinyl acetate and polymethyl methacrylate. Using X-ray photoemission spectroscopy we measured significant variations in the core binding energies and lineshapes as we varied both the metal and the substrate atoms. These changes can be related to both differences between the intrinsic properties of the metal atoms as well as to differences in the interactions with the substrates. In the following sections we describe the details of... 

The interfaces formed by evaporating copper, nickel and chromium layers on polystyrene, polyvinyl alcohol, polyethylene oxide, polyvinyl methyl ether, polyvinyl acetate and polymethyl methacrylate have been studied with X-ray photoemission spectroscopy (XPS). At submonolayer coverages of the metals, the peak positions and widths of the metallic electron core levels vary significantly from one polymer substrate to another. Most of... 

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