Photoelectron emission microscopy

The PEEM technique (photoelectron emission microscopy),58 which additionally allows for spatial resolution of about 1 mm2. 

Imbihl, Kiskinova, Janek and coworkers67 have also used XPS and spatially-resolved photoelectron emission microscopy (SPEM) to investigate oxygen backspillover between YSZ and evaporated microstructured Pt films prepared using microlithographic techniques (Figure 5.38). 

Figure 7.24 Photoelectron emission microscopy images of two Fe304 surfaces that were used as model catalyst in the dehydrogenation of ethylbenzene to styrene at 870 K, showing carbonaceous deposits (bright). These graphitic deposits grow in dots and streaks on a surface of low defect density, but form dendritic structures on surfaces rich in point and step detects (from Weiss et al. f731).

Fig. 7.28 Ell ipsometry for surface imaging (EMSI) images from a Pt(110) surface during CO oxidation at 480 K and total pressure in the 10-2 mbar range. The image represents an area of about 1 mm2. Electron microscopic techniques such as photoelectron emission microscopy would be able to image at higher resolution, but cannot be applied at these relatively high pressures. (From [80]).

The photoelectron emission microscopy (PEEM) investigations of Imbihl and coworkers [91] (Eigure 22) have nicely confirmed not only the potential-controlled variation in the work function of model Pt electrodes deposited on YSZ but also the Eermi-level pinning between Pt and YSZ. 

Among the related methods, specific experimental designs for applications are emphasized. As in-system synchrotron radiation photoelectron spectroscopy (SRPES) will be applied below for chemical analysis of electrochemically conditioned surfaces, this method will be presented first, followed by high-resolution electron energy loss spectroscopy (HREELS), photoelectron emission microscopy (PEEM), and X-ray emission spectroscopy (XES). The latter three methods are rather briefly presented due to the more singular results, discussed in Sections 2.4-2.6, that have been obtained with them. Although ultraviolet photoelectron spectroscopy (UPS) is an important method to determine band bendings and surface dipoles of semiconductors, the reader is referred to a rather recent article where all basic features of the method have been elaborated for the analysis of semiconductors [150]. 

The highest lateral resolution aehieved in this work was 1 pm, as displayed in the ToF-SIMS maps in Fig. 7. The results clearly show that the eontaet area after a ehip-on-disk test is not homogeneous, but is eomposed of individual scars. In the region where the wear is more severe, there is evidence of zinc phosphate, whereas the less-worn areas of the contact region are covered by an iron phosphate layer. Similar information has also been obtained by means of photoelectron emission microscopy (micro-XAS) [24] this technique allows spatially resolved elemental analysis to be performed, although the data are difflcult to quantify. 

Most of the published work deals with films produced by these alternative additives to ZnDTPs under tribological and/or pure thermal conditions. Several analytical techniques have been employed to characterize the reaction layers, such as X-ray photoelectron spectroscopy (XPS) [7, 12, 14, 25, 26], X-ray absorption spectroscopy (XAS) [13, 21-24], X-ray photoelectron emission microscopy (X-PEEM) [24], scanning electron microscopy (SEM) [20, 21], Fourier transform infrared spectroscopy (FT-IR)... 

This was further confirmed by a study of Gong et al. (2012) using X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron emission microscopy... 

Christensen S, Lanke UD, Haines B, Qaqish SE, Paige MF, Urquhart SG. (2008) Structural and compositional mapping of a phase-separated Langmuir-Blodgett monolayer by X-ray photoelectron emission microscopy. J El Spec Rel Phenom 162 107-114. 

Microscopy contains scanning tunneling microscopy (STM) and photoelectron emission microscopy (PEEM). 

H. Hibino, H. Kageshima, M. Kotsugi, F. Maeda, F.-Z. Guo, Y. Watanabe, Dependence of electronic properties of epitaxial few-layer graphene on the number of layers investigated by photoelectron emission microscopy. Phys. Rev. B 79, 125431 (2009)... 

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