Photoelectron mass spectroscopy

NIRMS = noble-gas-ion reflection mass spectrometry OSEE = optically stimulated exoelectron emission PES = photoelectron spectroscopy PhD = photoelectron diffraction SIMS = secondary ion mass spectroscopy UPS = ultraviolet photoelectron spectroscopy ... 

The interface properties can usually be independently measured by a number of spectroscopic and surface analysis techniques such as secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy (XPS), specular neutron reflection (SNR), forward recoil spectroscopy (FRES), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), infrared (IR) and several other methods. Theoretical and computer simulation methods can also be used to evaluate H t). Thus, we assume for each interface that we have the ability to measure H t) at different times and that the function is well defined in terms of microscopic properties. 

The most widely used techniques for surface analysis are Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), Raman and infrared spectroscopy, and contact angle measurement. Some of these techniques have the ability to determine the composition of the outermost atomic layers, although each technique possesses its own special advantages and disadvantages. 

At present, most workers hold a more realistic view of the promises and difficulties of work in electrocatalysis. Starting in the 1980s, new lines of research into the state of catalyst surfaces and into the adsorption of reactants and foreign species on these surfaces have been developed. Techniques have been developed that can be used for studies at the atomic and molecular level. These techniques include the tunneling microscope, versions of Fourier transform infrared spectroscopy and of photoelectron spectroscopy, differential electrochemical mass spectroscopy, and others. The broad application of these techniques has considerably improved our understanding of the mechanism of catalytic effects in electrochemical reactions. 

In this study, we extend the range of inorganic materials produced from polymeric precursors to include copper composites. Soluble complexes between poly(2-vinylpyridine) (P2VPy) and cupric chloride were prepared in a mixed solvent of 95% methanol 5% water. Pyrolysis of the isolated complexes results in the formation of carbonaceous composites of copper. The decomposition mechanism of the complexes was studied by optical, infrared, x-ray photoelectron and pyrolysis mass spectroscopy as well as thermogravimetric analysis and magnetic susceptibility measurements. 

Photoelectron spectroscopy of free radicals has been utilized for detection of radicals. It can be via resonance photoexcitation and photoionization (e.g. ZEKE) or non-resonance photoionization (e.g. single-photon VUV photoionization). The photoelectron spectroscopy of free radicals has been reviewed in 1994 by Chen.5 A recent review on mass spectrometry, photoelectron spectroscopy, and photoionization of free radicals by Sablier and Fujii is available.72 It is worthwhile to point out that mass spectrometry by photoionization offers some advantage for the detection of radicals, in comparison with the conventional mass spectroscopy by electron-impact... 

Spectroscopy produces spectra which arise as a result of interaction of electromagnetic radiation with matter. The type of interaction (electronic or nuclear transition, molecular vibration or electron loss) depends upon the wavelength of the radiation (Tab. 7.1). The most widely applied techniques are infrared (IR), Mossbauer, ultraviolet-visible (UV-Vis), and in recent years, various forms ofX-ray absorption fine structure (XAFS) spectroscopy which probe the local structure of the elements. Less widely used techniques are Raman spectroscopy. X-ray photoelectron spectroscopy (XPS), secondary ion imaging mass spectroscopy (SIMS), Auger electron spectroscopy (AES), electron spin resonance (ESR) and nuclear magnetic resonance (NMR) spectroscopy. 

Nitrogen physisorption measurements indicate large internal surface area of 402 m /g and quite narrow distribution of pore sizes with peak maximum at 3.1 nm (Fig. 7). The framework wall thickness was estimated to be 1.9 nm. The oxidation state of Ge framework as probed with X-ray photoelectron spectroscopy (XPS) and time-of-fiight secondary ion mass spectroscopy (ToF-SIMS) techniques is close to zero. 

The way in which fluoride is taken up by glass-ionomers has been studied using surface analysis techniques. Dynamic secondary ion mass spectroscopy (SIMS) shows that most of the fluoride becomes concentrated in the surface [248]. Its concentration with depth varies as an error function relationship [248]. X-ray photoelectron spectroscopy (XPS) has suggested that fluoride taken up becomes associated with calcium [249]. However, the form of this association is unclear, because calcium fluoride as such is very insoluble, and when added to a fluoride-free glass-ionomer cement, caused no fluoride to be released [234]. It therefore seems unlikely that the calcium-fluoride association results in formation of Cap2, and further research is necessary to determine the precise nature of the calcium-fluoride association, and thus to resolve this paradox. 

The oxidation and degradation of small hydrocarbon molecules have many similarities (Fig. 8.10). These reactions have been studied extensively by a variety of surface techniques such as Thermal Desorption (TDS), ion mass spectroscopy, specular infrared spectroscopy, Secondary Ion Mass Spectroscopy (SIMS), X-ray Photoelectron Spectroscopy (XPS), and so on. The reaction pathways and the final products depend on the type of oxygen-bearing species, which in turn depends on the doping and morphology of the oxide layer. This is the major reason why results obtained with different oxide sensors in different laboratories do not always agree. 

Some of the techniques described in this chapter used most widely today are Auger electron spectroscopy, X-ray photoelectron spectroscopy, electron-probe micro-analysis, low energy electron diffraction, scanning electron microscope, ion scattering spectroscopy, and secondary ion mass spectroscopy. The solid surface, after liberation of electrons, can be analyzed directly by AES, XPS, ISS, and EPMA (nondestructive techniques), or by liberation of ions from surfaces using SIMS (involving the destruction of the surface). Apart from the surface techniques, reflectance-absorbance infrared (RAIR) spectroscopy has also been employed for film characterization (Lindsay et al., 1993 Yin et al., 1993). Some... 

Technique abbreviations AES = Auger Electron Spectroscopy EXAFS = Extended X-Ray Absorption Fine Structure ISS = Ion Scattering Spectroscopy SIMS = Secondary Ion Mass Spectroscopy UPS = Ultraviolet Photoelectron Spectroscopy XANES = X-Ray Absorption Near Edge Structure XPS (or ESCA) = X-Ray Photoelectron Spectroscopy bAnalysis type C = chemical, E = elemental... 

ESCA UPS SIMS STM IR UV electron spectroscopy for chemical analysis ultra-violet photoelectron spectroscopy secondary ion mass spectroscopy scanning tunneling microscopy infra-red ultra-violet... 

Frictional Force Microscopy Fourier-transform infrared spectroscopy scanning electron microscope surface force apparatus Secondary ion mass spectroscopy scanning tunneling microscope X-ray photoelectron spectroscopy bovine serum albumin immunoglobulin G... 

The chemical nature and composition of catalyst surfaces are essential parameters for understanding catalytic reactivity. Electron spectroscopies, mainly Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), Secondary Ion Mass Spectroscopy (SIMS) and Ion Scattering Spectroscopy (ISS) allow such information to be obtained. AES and XPS are most likely to provide meaningful data if the surface region of the solid is homogeneous over a depth several times the inelastic mean free path of the emitted electrons. 

Surface analytical methods — Important ex situ methods for surface analysis are X-Ray Photoelectron Spectroscopy (XPS) UV-Photoelectron Spectroscopy (UPS), Auger Electron Spectroscopy (AES), Ion Scattering Spectroscopy (ISS), Rutherford Backscattering (RBS), Secondary Ion Mass Spectroscopy (SIMS), Scanning Electron Microscopy (SEM), Electron Microprobe Analysis (EMA), Low Energy Electron Diffraction (LEED), and High Energy Electron Diffraction (RHEED). 

X-ray photoelectron spectroscopy (XPS), SIMS (Secondary Ion Mass Spectroscopy) and nuclear-reaction-based analyses (like RBS - Rutherford Backscattering -, and PIXE - Proton Induced X-ray Emission) have already proven their complementary potentialities. 

---