Electronic Structure of Surfaces

Although physical studies of the electronic structure of surfaces have to be performed under UHV conditions to guarantee clean uncontaminated samples, the technique does not require vacuum for its operation. Thus, in-situ observation of processes at solid-gas and solid-liquid interfaces is possible as well. This has been utilized, for instance, to directly observe corrosion and electrode processes with atomic resolution [5.2, 5.37]. 

We have developed a theory that allows to determine the effective cluster interactions for surfaces of disordered alloys. It is based on the selfconsistent electronic structure of surfaces and includes the charge redistribution at the metal/vacuum interface. It can yield effective cluster interactions for any concentration profile and permits to determine the surface concentration profile from first principles in a selfconsistent manner, by... 

Electronic Structure of Surfaces and Interfaces in Conjugated Polymers... 

Another way to monitor the expected changes in the metal electronic structure is to look at the adsorbed molecules, which are sensitive in their properties to the changes in the electronic structure of surface metal atoms. Such a molecule is CO and the frequency of the CO stretch vibrations ( v(CO)) is a sensitive detector of the direct- and back-donation upon adsorption of CO. It has been reported, that v(CO) decreases for the VIII group metal by alloying of Pd with Ag (22), Ni with Cu (23), but also when mixing Ni with Co (24). This has been first explained (25) as an indication for an increased backdonation due to an assumed electron shift Cu Pt,... 

Here, we demonstrate clear and direct evidence for the modified electronic structures of surface Pt atoms in Pt-Co and Pt-Ru by using EC-XPS [Wakisaka et al., 2006]. The sample electrode was transferred between an XPS chamber and an electrochemical (EC) chamber without exposure to air (to minimize contamination of the surface). All photoelectron spectra, including the valence level region) were taken by using a monochromatic Al Ka (hv = 1486.58 eV). The uncertainty of binding energy measurement was less than + 0.03 eV. 

At present, the STM has been demonstrated to yield spectroscopic information regarding the spatial, vibrational, and electronic structure of surfaces. In all of these areas, the STM is complementary to other existing techniques. Also, and in many potential applications, STM possesses unique features and capabilities. These capabilities are discussed in the section below. 

From the perspective of this symposium, analysis of the atomic dynamics and electronic structure of surfaces constitutes an even more exotic topic than surface atomic geometry. In both cases attention has been focused on a small number of model systems, e.g., single crystal transition metal and semiconductor surfaces, using rather specialized experimental facilities. General reviews have appeared for both atomic surface dynamics (21) and spectroscopic measurements of the electronic structure of single-crystal surfaces (, 22). An important emerging trend in the latter area is the use of synchrotron radiation for studying surface electronic structure via photoemission spectroscopy ( 23) Moreover, the use of the very intense synchrotron radiation sources also will enable major improvements in the application of core-level photoemission for surface chemical analysis (13). 

New developments in the quantum chemistry methodology, make it possible to obtain new data concerning the electronic structure of surface of zirconia nanoparticle and the dopants in it. 

M. Lannoo and P. Friedel, Atomic and electronic structure of surfaces. Springer Series in Surface Science, Vol. 16, Springer Verlag, Berlin, Heidelberg, New York, 1991. 

Introduction.—Without doubt the most important recent advance in field emission techniques has been the development of field emission spectroscopy. It has led to a critical re-examination of the theory of field emission and contributed to the recent considerable advance in understanding of the electronic structure of surfaces and of chemisorbed species. A comprehensive review of the theory and practice has been... 

A number of fundamental studies explore catalyst activity at an atomistic scale. DFT calculations can reveal how the rates of surface processes depend on the local electronic structure of surface atoms [233-238]. Monte Carlo simulations and mean-field approaches can incorporate this information in order to rationalize the effects of nanoparticle sizes and surface structure on the overall rates of current conversion [233, 239], Thereby the nontrivial dependence of reactivity on particle size could be explained. 

Lannoo, M. Friedel, P. Atomic and Electronic Structure of Surfaces. Volume 16 in Springer Series in Surface Sciences. Berlin, Heidelberg Springer-Verlag, 1991. 

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