Shakeup satellites

It is also possible that Pd is reduced to a second PdHx phase. When the metalhc Pd chemical shift was compared to PdHx as reported in the hterature (13), the core level Pd 3d5/2 binding energy shift was only 0.2 eV. The article also found that the asyimnetiy of the 3d peak was slightly reduced, and a shakeup satellite peak (indicated by the arrow in Figure 15.6) disappeared. However, in the presence of metalhc Pd, we cannot determine whether a second PdHx phase is present. 

Fig. 16. X-ray photoelectron spectra of Rb 4s in RbCl and RbF shakeup effects are responsible for the satellites. The position of the 4s24p45s (2S) level, 9.56 eV more tightly bound than the 4s14/>6 (2S) state represented by the sharp peak in each case, is indicated (see text). Ref. (40)...

Fig. 17. The 2p X-ray photoelectron spectra of Cu in CuO and Cu metal. Shakeup satellites appear in the oxide spectrum but not in that of the metal. Ref. (42)...

Shakeup Satellites. An unusual feature in many spectra is the shakeup satellite, a line or lines usually several eV lower in kinetic energy than the parent photoelectron line. It arises vdien the photoelectric transition has a significant probability of generating a final ion in an excited state. The extra energy in the excited state is reflected in the energy separation of the satellite from the main line. A common example in organic systems... 

Rare earth ions also exhibit complex shakeup satellite patterns. That of Ce3d in Ce02 is especially noteworthy in the fact that two satellites for each of Ce3d -2 and Ce3d. 2 appear, one of them more intense than the primary line and separated from it by as much as 16 eV (Fig. 3). Actinide compounds also exhibit many satellites in their spectra. Wide use of these features in analytical work awaits collection of these spectra in a comprehensive review. 

An interesting observation has been that of intense shakeup satellites on high energy KLL Auger lines for such diamagnetic species as K, Ca, and Ti compounds (, 26). When anodes... 

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. 

Cls photoemission shakeup satellites for the CO molecule are obtained using the... 

KEYWORDS shakeup satellite, spin-polarized DV-Xa method, transition state concept, CO, XPS. 

The main peaks in X-ray Photoelectron Spectroscopy (XPS) for molecules appear because of the photoionization of core electrons. In addition, satellite peaks on the high binding energy side of the main peak have often been observed. These peaks are generally referred to as shakeup satellite peaks. In the sudden approximation, the shakeup process which accompanies photoionization can be considered as a two-step process. First, a core electron is emitted as a photoelectron, creating an inner shell vacancy. In the next step, electron(s) in the same molecule transfer from valence orbital(s) to unoccupied orbital(s) with relaxation of orbital energies. It is important to study these satellites in order to understand the valence and excited states of molecules (1). 

Satellite structures can be easily observed in simple molecules. The Cls spectrum of CO is especially interesting, because this molecule can be considered to be a typical example of a small unsaturated molecule. The satellite peaks which accompany the Cls spectrum of CO have been studied both experimentally and theoretically by many researchers. Experimental studies have been performed by Gelius (2), Hemmers et al. (3), Schirmer et al. (4), and Reich et al. (5). Schirmer et al. (4) proved that some satellite peaks caused by inelastic scattering appear near to the shakeup satellite peaks which accompany Cls photoionization in comparison with CO energy loss spectra. Hemmers et al. (3) and Reich et al. (5) performed higher resolution measurement. In particular,... 

In the present work we tried to interpret the satellite peaks which accompany the CO Cls spectrum as a shakeup process. The values we calculated are used to assign the experimental spectrum. The results are also compared with assignments by other calculation methods. 

Next, we describe how we calculate the satellite peak energies which are observed for the shakeup transition in XPS. The energy of the shakeup peaks observed in XPS can be represented by the wave functions ... 

Cls photoemission shakeup satellites for the CO molecule were calculated with the spin-polarized discrete variational Xa method. The transition state method was applied to the estimation of multiplet peak positions for the shakeup transitions and the results are in reasonable agreement with the experimental values. 

The present results indicate that the DV-Xa method in combination with the transition state method is quite useful for the study of shakeup satellites in XPS for molecules. 

In atoms and molecules, shakeup satellites, corresponding to internal electronic transitions, are routinely observed using photoelectron and resonant Raman spectroscopy. In particular, shakeup satellites can be observed in the two particle spectrum, i.e., when two holes are left in the final state of an atom after electron emission. Satellite s strength can be strongly enhanced in the presence of a resonant intermediate state. For example, in copper atoms, the incident photon can first excite the core 3p electron to the 4s shell the core hole then decays to the 3d shell through the Auger process (with electron ejected from 3d shell) leaving two 3d holes in the final state [48]. For recent reviews of extensive literature the reader is referred to Refe. [49,50]). 

Figure 4 Emission spectrum for Ai = 3A2. In low-frequency domain, the single-particle peaks acquire weak many-body shakeup satellites. In high-frequency domain, the heights f the parent (lw /A = 1) and satellite ( w /A = 1 -t-1/2) peaks are close to each other.

The above result illustrates how the structure of the spectrum evolves as the frequency departs from the Fermi edge. For = ln each single-paxticle peak, o = IA acquires a weak shakeup satellite at lu = I + )A. In the opposite limit, 1, the oscillator strength of an... 

Figure 21. Evolution of the shakeup satellite of the C l.v peak of PES during Ar+ beam treatment. (From Ref. 120.)...

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