4f7/2 peak

Figure 10. Mg -excited ESCA spectra of some lead compound mixtures, acquired in the region of the kinetic energy corresponding to the Pb 4f (4f5/2 and 4f7/2> peak-doublet transitions. The lack of collinearity among the compcsients and mixtures makes the Kalman filter separation not feasible, (a) Pb02+PbS04 (60 40) (b) Pb02+Pb(C03> (60 40) (c) Pb02+Pb(N03)2+Pb(C03) (35 35 30), (d) Pb02++Pb(C03)+Pb(S04) (20 20 60) (c) pure Pb(C03) (f) pure Pb(S04). (From Fresenius J Anal. Chem (1993) 345 490, with permissirai).

II. c XPS spectra were recorded using a SSI-X probe (SSX-100-206) spectrometer of FISONS with monochromatised AIK, radiation.The spectrometer energy scale was calibrated using the Au 4f7/2 peak ( binding energy 93.98 eV). With the analyzer resolution used (50 eV) for rea>rding individual peaks the full v th at half maximum of Au 4f7/2 peak was of 1.0 eV. 

Fig. 24. Comparison of YbAlj divalent portion of spectrum (upper frame) to that of pure Yb film data appropriately shifted to coincide with YbAl-. The similarity is striking. Middle fr-ame blow-up of the 4f7/2 peaks to show that the high binding eneigy side of the peaks coincides while the low binding energy side of YbAl. appears to have been cut by a Fermi function. Lower frame Yb film data cut by Fermi function. Note similarity to YbAlj. (From Joyce et al. 1996.)...

In Yb compounds the phonon broadening was estimated from a measurement of pure Yb metal, which, as we have already seen in fig. 24, displays 4f spectra similar to those of the heavy fermion compounds despite the position of the 4f7/2 peak at —1 eV below E. The temperature dependence of these levels, now due entirely to phonon broadening, is shown in fig. 29. The data were fitted at each temperature with Gaussian broadened Doniach-Sunjic (1970) lineshapes and separated into bulk and surface components. The fits are overlaid in the upper frame, normalized to equal integrated intensities. A substantial apparent temperature dependence is observed even in the absence of the Fermi function cut-off, and in the absence of any spectral weight loss. The 300 K spectra are broadened by 130meV over the 25 K spectra (added as root mean square). 

Fig. 42. ARPES data for CeBe,3(100) and CeBe,3(110). Two angles are shown for CeBe,3 (100) with the 4f7/2 peak showing about 100 meV of dispersion, while the 4f5/j peak shows a large amplitude modulation. The inset shows the imagined band structure which could produce such an effect (from Andrews et al. 1996).

Dendrimers containing Pt " or Pt-metal nanoparticles are easily attached to Au and other surfaces by immersion in a dilute aqueous solution of the composite for 20 h, followed by careful rinsing and drying [59,129]. Therefore it is possible to use X-ray photoelectron spectroscopy (XPS) to determine the elemental composition and the oxidation states of Pt within dendrimers. For example, Pt(4f7/2) and Pt(4f5/2) peaks are present at 72.8 eV and 75.7 eV, respectively, prior to reduction, but after reduction they shift to 71.3 eV and 74.4 eV, respectively, which is consistent with the change in oxidation state from -i-2 to 0 (Fig. 13 a]. 

Similarly, peak Bi corresponds to transitions to the (4f5/2)(5d ,) configuration, while peak B2 corresponds to transitions to the (4f7/2)(5d ,) configuration. These results also indicate that the splitting between peak Bi and B2 originates from the spin-orbit splitting of Pr 4f levels. Compared with peaks A and B, the compositions of peaks C and E are complicated. Peak C corresponds to transitions to the mixed states of the (4f5/2)(5dc), (4f7/2)(5dc), (4f5/2)(5d ), and (4f7/2)(5drf) configurations which simply corresponds to the transitions from 4f states to... 

The peaks a. a2 arise from the transitions to (4f5 2)(5d ) configuration, <23 to (4f7,2)(5d ). 4 to transitions to the mixed states of (4fs 2)(5d/,) and (4f7 2)(5dj). Therefore, the difference between peaks a and a2 originates from the multiplet splitting within (4fs 2)(5dfl) configuration, i.e., the interaction between the 4fs 2 electron and 5da electron, while the difference between peaks a, a2 and peak 03 originates from the spin-orbit splitting of the Pr 4f state. Peak 04 arises from the transitions to Pr 5d/, levels. 

Figure 3 (C) shows two XPS peaks of Bi 4f7/2. Values of the binding energies are Ebi=158.5eV and Eb2=159.1eV, respectively. They correspond to valence states of Bi as Bi and Bi ". The amount of Bi " is larger than that of Bi in the Bi ions of the 2223 phase. The experiment results showed that the Cu exists as +2 and +1 valences in the 2223 phase. There are no Cu ions with a +3 valence. The Bi is presents in +3 and +4 valences. Doping of Sn-Cl or Co ions has been found to obviously reduce the induction period of the 2223 phase appearance at the sintering temperature.

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