SIMS images

TOP SIMS imaging can also be used to detect extremely small particles on a variety of substrates, e.g. silicon wafers or photographic films [3.40]. Figure 3.16 depicts... 

Fig. 3.16. High-resolution TOF SIMS images of silver bromide and silver chloride crystals.

Fig. 3.23. Scanning SIMS image of the carbide structure of a high-speed steel [3.52]. In the V distribution different phases (MC and M2C) are visible. The Al distribution shows the shell struc-...

Fig. 3.24. Di rect-imaging mode SIMS image of a passivation layer on a niobium alloy [3.54], Boron enrichment at the interface is not visible with EPMA. Measurement time 10 s image diameter 150 pm primary ions OJ primary energy 5.5 keV.

Visually, failure was mostly eohesive within the adhesive (see Figs. 34 and 46). However, there was a small area of apparent interfacial failure ( initiation zone ) located at one end of each substrate. Line scans were eondueted aeross the initiation zone, from the edge of the substrate to the area of cohesive failure within the adhesive. From the line scans, it was apparent that there were patehes of polymer present in the initiation zone, even when failure appeared to be interfaeial (see Fig. 46). SIMS images of the initiation zone were constructed for various mass numbers (see Figs. 47-49). The images showed well-defined cation-rieh... 

Fig. 47. TOF-SIMS image highlighting cation-rich areas, indicating that local cathodic cells occur within the initiation zone. Image shows (A) total counts, (B) m/z = 40, (C) m/z = 52 and (D) m/z = 24. Reproduced by permission of John Wiley and Sons from Ref. [57. ...

Fig. 49. TOF-SIMS images showing that the cation-rich areas in the initiation zone do not corre.spond to polymer-rich areas (A) mjz. = 88 on 24 (B) tnjz = 77 + 91 on 24. Reproduced by permission of John Wiley and Sons from Ref. [571.

Fig.9. SIM image of a monolayer of didodccylbenzcnc adsorbed on pyrolytic graphite from a phenyloctane solution. The area shown corresponds to 7.2 x 4.7 nm2 [37]. The strong features represent the benzene rings and the ordered arrangement of side groups is clearly resolved...

S.G. Nikolov, H. Mutter and M. Grasserbauer, De-noising of SIMS images via wavelet shrinkage. Chemom. Intell. Lab. Syst., 34 (1996) 263-273. 

M. Walkenstein, H. Hotter, C. Mittermayr, W. Schiesser and M. Grasserbauer, Classification of SIMS images using a Kohonen network. Anal. Chem., 69 (1997) 777-782. 

Figure 4.7. Boron scanned ion beam mass spectrometry (SIMS) image of a B-doped diamond specimen. The image is 430 pm in width, and the variation of B intensity from one grain to another is approximately a factor of 8. (Reproduced by permission of Professor J. W. Steeds.)...

Fig. 830. Schematic dismantling of the m + 3 dimensions of multidimensional SIMS images each original data layer contains five dimensions A,B,C = f(lx, ly) in the case represented here...

Wickes BT, Kim Y, Castner DG (2003) Denoising and multivariate analysis of time-of-flight SIMS images. Surface Interface Anal 35 640... 

Wolkenstein M, Hutter H, Nikolov SG, Grasserbauer M (1997a) Improvement of SIMS image classification by means of de-noising. Fresenius J Anal Chem 357 783... 

Valuable results with Tof-SIMS imaging have been obtained e.g., with paper samples. The distribution of papermaking chemicals on the surface of coated and uncoated papers is very important for its further treatment, such as printing. Figure 16 [70] is an example of use of the technique for chemical microscopy analysis of paper surfaces. 

Figure 16 ToF-SIMS images of total ion current, AKD (alkyl ketene dimer) size, optical brightener and hexosan distribution on multipurpose paper surface after coating with Au-Pd. Reproduced from Fardim and Holmbom [70], with permission from Elsevier. 2005.

SIMS imaging was theoretically invented in 1949 by Herzog and Viehb of the Vienna University in Austria. The first SIMS device was completed by Liebel and Herzog in 1961 with the support of the National Aeronautics and Space Administration (NASA) and was used to analyze metal surfaces. However, it was not suitable for analyzing biological macromolecules because the second electronic ion beam breaks the molecules into atoms. 

Figure 15.3 Example of the use of a region of interest (ROI) on ToF SIMS images to obtain a more specific spectrum. On account of the selected area on the image, signals from fatty acids are emphasized on the selected spectrum (see colour Plate 3)...

Figure 15.14 Study of the sample from the Dogon statuette 71.1935.105.169. (a) Optical microphotograph (b) SEM micrograph showing the layer structure ToF SIMS images of (c) proteins, (d) polysaccharides and (e) stearic acid (f) superposition of the distribution of poly saccharides and stearic acid (see colour Plate 9)...

In this chapter a number of the recent applications of imaging of small molecules with the use of SIMS imaging will be presented. 

Figure 13.2. TOF-SIMS images of blue (m = 413 u) and green (m = 641 u) pigments of color filter array. Above each image the primary ion gun and the measurement time is displayed. Corresponding signal intensity of emitted secondary ions from an analyzed surface is given under suitable image. (Reprinted from Kollmer, F. 2004. Appl. Surf. Sci., 231-232 153-158. With permission from Elsevier.) (See color insert.)...

TOF-SIMS images (Figs. 13.5 and 13.6) illustrate the ability to detect changes in the dispersion (uniform or presence of metal clusters) of the active phase in supported-oxide catalysts. Figure 13.5 shows nearly uniform distribution of molybdenum. The surface contamination with NH4+ ions coming from a precursor, which were not removed during the catalyst preparation process, is also observed. Cobalt clusters in the range of several micrometers are clearly visible in Fig. 13.6. 

Figure 13.9. TOF-SIMS images of a silicon wafer taken from the fields 277 x 277 pm2 155 x 155 pm2, 39 x 39 pm2, and 7.8 x 7.8 pm2. On the highest magnification image the existence and distribution of trace impurities of ions such as Na, Ca, B02, and CxHy are observed. (See color insert.)...

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