Spectroscopic methods SIMS

Further structural information is available from physical methods of surface analysis such as scanning electron microscopy (SEM), X-ray photoelectron or Auger electron spectroscopy (XPS), or secondary-ion mass spectrometry (SIMS), and transmission or reflectance IR and UV/VIS spectroscopy. The application of both electroanalytical and surface spectroscopic methods has been thoroughly reviewed and appropriate methods are given in most of the references of this chapter. 

Other problems in adhesion may be tackled by studying the surface of the material after fracture. Mass spectroscopic methods like SIMS may reveal transfer of molecular fragments from the one component towards the other one. 

Functionalization of biomedical materials controlled by high sensitivity of spectroscopical methods like ToF-SIMS and XPS allow one to build sensors and to control adhesion characteristics in a nicely controlled manner ... 

In sim infrared (IR) spectroscopy is a spectroscopic method for the infrared spectral range which can be used in defined environments during preparation, modification, function, and reaction or analysis in natural environment. In this contribution especially liquid environments are considered with the focus on the mid-infrared (MIR) spectral range from 2.5 to 16 pm. 

The development of variable temperature />i sim spcclroelcctrochemical techniques has enabled us to probe the electronic characteristics of the frontier orbitals of redox-active materials. The important feature of these methods is that the electrosynihesiscd species is generated inside the cavity of the spectrometer. Thus the electron transfer product, which is usually air and/or moisture sensitive, can be studied directly by the chosen spectroscopic method without the necessity of transporting the unstable solution from the eicctrosynthesis cell to the spectrometer. Most spectroscopic methods can be coupled with electrochemical techniques, for example, infrared, raman, resonance raman, uv/vis, epr have all been reported ... 

Electrochemical and spectroscopic methods have been used to investigate irreversible-loss mechanisms of lithium intercalation in disordered polymethacrylo-nitrile carbons. Voltammetric measurements show that the solvent readily decomposes at potentials 1.2 V positive of the reversible lithium potential. Evidence for hydrocarbon, carbonate and alkylcarbonate formation in the surface film is found with the help of combined XPS and SIMS analysis. 

Surface analytical techniques can be classified in terms of the excitating and emitted probe cfr. Table 4.4). The penetration of the physical probe increases fl om ions (ISS, RBS, SIMS) to electrons (XPS) and finally photons (UV/VIS, IR, XRF, etc.). Amongst the photon beam techniques which show some degree of surface sensitivity, in practice only XPS, total reflection X-ray fluorescence (TXRF) and laser-induced mass spectroscopic methods (LMMS),... 

The chemical structure of the membrane can be analyzed with spectroscopic methods, of which the Fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR) method is the most utilized. However, Raman spectroscopy and IR spectroscopy complement each other, and, thus, if both methods arc used, the information obtained on the membrane chemical structure is quite comprehensive. If only information from the membrane skin layer is needed, the most surface-sensitive methods—X-ray photoelectron spectroscopy (XPS) and lime-of-flight secondary ion mass spectroscopy (TOF-SIMS)— have to be used. 

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. 

IR, Raman, NMR, ESR, UPS, XPS, AES, EELS, SIMS) [1]. However, some industrial carbon materials such as amorphous carbon films and carbon black cannot be easily characterized from the local-structure point of view by these methods, because these materials usually take amorphous and complex structures. Recently, soft X-ray emission and absorption spectroscopy using highly brilliant synchrotron radiation [2] has been utilized to characterize various carbon materials, because information on both the occupied and unoccupied orbitals, which directly reflect the local structure and chemical states, can be provided from the high-resolution soft X-ray measurements. We have applied the soft X-ray spectroscopy to elucidate the local structure and chemical states of various carbon materials [3]. Additionally, we have successfully used the discrete variational (DV)-Xa method [4] for the soft X-ray spectroscopic analysis of the carbon materials, because the DV-Xa method can easily treat complex carbon cluster models, which should be considered for the structural analysis of amorphous carbon materials. 

Secondary-ion mass spectrometry (SIMS) can be used to detect the presence and the depth distribution of a specific impurity by etching out ions (secondary ions) from a material with a Cs+ or C>2+ ions probe, and measuring the impurity peak by mass spectrometry. This method provides a chemical signature of the impurity, with possible interferences, however, between atomic and molecular ions with the same masses and charges. It cannot discriminate between the isolated impurity and complexes or precipitates in which it is involved. Its sensitivity depends on the background of impurity. SIMS has been used for the detection of boron acceptor in CVD diamond [39]. These absolute methods of concentration measurements have been combined with spectroscopic measurements, which are easier to perform, to produce spectroscopic calibration factors. 

Surface characterization of mixed oxide coatings [37] by spectroscopic techniques shows surface enrichment with one of the metals. The surface of (H + Ru)02 appears to be enriched with Ti [38,39], and that of (Ru + Ir)02 with Ir [40-42]. The degree of enrichment depends on the method of preparation [40,43]. SIMS analysis, however, does not reveal the surface enrichment of Ti in the commercial RUO2 +1102 coatings [44],... 

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