O Is XPS spectra

Figure 29. C Is and O Is XPS spectra for fresh, precycled, and stored graphite anodes. (Reproduced with permission from ref 294 (Figure 17). Copyright 2002 The Electrochemical Society.)...

Fig. 3.17 Real-time O Is XPS spectra during the exposure of a Rh(lll) surface to CO at three different temperatures, along with uptake curves showing the XPS intensity of the two O Is components in the spectra calibrated to a surface coverage in monolayers. (Adapted from [S3]).

Figure 5. O Is XPS spectra of Pb phthalocyanine thin films after different treatments. a as preparation imder UHV(ultra-high-vacuum) conditions, b afler exposure of UHV-prepared films to air, c afler the air-exposed filmes in SOOmbar O2 at 423K[7].

Fig. 12. High-resolution O Is XPS spectra for Ma-AF TES2 from Table 2 (Durdureanu-Angheluta et al., 2011b)...

Figure 6-5. O Is XPS spectra from a NiC02O4 sample (a) after reduction and after (b) 12 h (c) 24 h and (d) 48 h under UHV conditions. The arrows show the positions of the three peaks usedfor fitting the spectrum in the lower panel. A linear back ound subtraction was used (Kim et al., 2000).

A series of C Is XPS spectra obtained during irradiation with 1,190 eV X-rays is shown in Fig. 8. Photolysis results in a decrease in intensity of the C-H and C-O peaks and an increase in the C-M intensity. The C-H peak also shifts to lower binding energy. This shift is mainly due to C-O bond cleavage, which lowers the... 

Fig. 8 Series of C Is XPS spectra of (R)-2-butanol adsorbed on permalloy obtained sequentially while irradiating with 1,190-eV X-rays. The inset shows the area of the C-O peak component as a function of irradiation time...

Fig. 11. O U XPS spectra taken at three indicated points along the oscillatory cycle in CO oxidation on Pt(llO). The dotted CO2 partial pressure curve is from experiments the solid curve results from simulations. The XPS peak corresponding to subsurface oxygen can be seen at 532 eV when the reaction rate is at a minimum. (From Ref. 67.)...

The complex nature of the bonding structure in transition metal nitrides incorporates a mixture of covalent, metallic and ionic components [126]. The nature on this bonding leads to high hardness, chemical inertness and, good electrical conductivity of these mixed nitride thin films. In what follows, we describe the surface chemical alteration of both a control and oxidized Ti—Al—N films (i.e., two different types of deposition room temperature (A) and liquid N2 temperature (B)), by measuring the chemical shifts in the Ti (2p), Al (2p), O (Is) and N (Is) XPS spectra. 

Fig. 18. Deconvoluted XPS O (Is) and spectra of ambient (Ti,Al)N thin films, (a) TiAlN film short-term oxidized at 850 °C and (b) TiAlN film long-term oxidized at 850 °C. Possible peak identification 1) Ti02 2) AI2O3 3) mixed oxynitrides 4) absorbed OH 5) mixed oxides. Reprinted with permission from S. Seal et al., J Vac. Sci. Technol. A18(4), 1571, 2000, in press. Copyright (2000), American Vacuum Society.

Figure 5 shows the photoelectron spectra of O Is level for TiOx following temperature of calcination. The parameters of these spectra are given in Table 2. " e asymmetrical O Is XPS peak of the dried material indicates the presence of different oxygen spedes in this sample, respectively at 530.1 and 531.8 eV. The peak at 531.8 eV is attributed to OH group, and the ratio of the areas of these peaks ([0]/[0H] = 5,8) is compatible with the value estimated by TGA. 

Figure 5.35. Effect of electrochemical O2- pumping on the O Is spectrum of Pt/YSZ6 (A-C). XPS spectra at 400°C (A) AUWR=0, 1=0 (B) AUWr=1-2 V, 1=40 pA (C) 0 Is difference spectrum.6 Reprinted with permission from the American Chemical Society.

The technique of SPEM allows one to obtain XPS spectra from extremely small (-0.02 pm2) surface areas and thus one can study O Is spectra obtained from small (-0.02 pm2) spots on the Pt surface.67... 

Adsorption and Reaction of CO and CO2. The clean and oxygen-precovered Au(lll) surface does not chemisorb CO at temperatures down to 100 K. This was established by CO uptake experiments utilizing XPS and TPD. C(ls) and 0(ls) XPS spectra taken after a 10 L CO exposure to Au(lll) with O = 0 0/ 0.5 and 1.0 at 100 K showed no evidence for a new carbon-containing surface species, i.e., no adsorbed CO, CO2, or carbonate species is stable on the Au(lll) surface under these conditions. The area of the 0(ls) peak after CO exposure was slightly smaller for both oxygen precoverages, but this is attributed to background CO oxidation and the formation of CO2 which desorbs from the surface at 100 K (vide infra). 

No adsorption of carbon dioxide or oxygen was observed on either praseodymium chloride or oxychloride. This finding is consistent with the XPS results. The main peaks at 529 eV in the spectra for praseodymium oxychloride samples are also attributed to the lattice oxygen of the oxychloride while the peaks at 531 eV are assignable to O Is for praseodymium oxide, suggesting that the surfaces of the oxychloride samples are partially oxidized to praseodymium oxide. The 3d binding energy of 933 eV for praseodymium in the chloride and oxychloride implies that the valence of praseodymium is 3+, while the shoulder at 928 eV could be attributed to metallic praseodymium (77). 

The XPS data were obtained with an extensively modified AEI ES-100 photoelectron spectrometer. The samples were analyzed at a pressure typically < 10 g Torr. A magnesium anode (1253.6 eV) was used as the excitation source. The analyzed sample area was of the order of 5 mm2. Survey scans from 0 to 1000 eV were first obtained for each sample to confirm that only the expected elements were present on the fiber surfaces. Subsequently, high resolution spectra were obtained by slowly scanning — 20 eV binding energy windows that included the Si 2p, Al 2p, Ca 2p, B Is, O Is, and C Is photoelectrons, respectively. Integrated peak areas of the photoelectron spectra were determined. The sensitivity factors, which were independently obtained on this spectrometer with oxide standards, were then utilized in the determination of the surface atomic percent compositions of the fibers. 

---