Line scans, layer

Fig. 7.88 Scanning electron micrographs of cross-sections through interaction layers with superimposed Fe and Zn K, line scans across the layers (

The 28 scan and layer line scan functions are provided as an aid to obtaining better estimates of the unit cell parameters for the substance being studied and in assessing contributions from background scattering and overlapping diffraction maxima. 

In this example a polymer laminate film (for packaging) was examined, which was composed of nine layers (see Table 2), by both FTIR imaging and Raman line scan. For the IR measurements thin sections (5 pm) were cut. The central ethylene/vinyl acetate (EVA) copolymer layer is very soft, and holes can be seen in the visible image (Figure 12). 

A simple line scan with Raman microscopy, however, clearly showed the LLDPE-MAH layer as a ca. 5-p.m broad plateau from the evaluation of three different Raman band intensities (Figure 14). In this case a simple Raman line scan obviously is the better choice for a determination of the LLDPE-MAH layer thickness, superior even to IR-ATR imaging. We used three Raman bands... 

Figure 14 (a) Raman spectra of the individual layers 1, LLDPE-MAH 2, COPA 3, EVA (abscissa wavenumber (cm ), ordinate intensity in arbitrary units), (b) Raman line scan of polymer laminate using three different Raman bands (abscissa position in pm, ordinate intensity in arbitrary units). 

Fig. 3. p-XRF line scans evidencing the chemical variations of Zn (left), and Mo (right), across the transect of Fig. 1b. Segment AB = goethite-rich layer segment BC = hematite-rich layer.

Fig. 14. A grid superimposed on the basal plane of a triangular single-layer M0S2 nanocluster. The intersections of the white lines indicate the sulfur atomic positions on the basal plane. At the edges, the protrusions are observed to be shifted out of registry with the basal plane lattice. An STM line scan across the bright brim of the single-layer M0S2 nanocluster is illustrated on the right. The arrow indicates the direction and position of the scan in the image.

Nanotubes represent the typical nano-objects and this presentation would not be representative without at least one example. The high resolution image on the left-hand side of Figure 5 represents a nanotube, the detailed composition of which cannot be deduced from the image or any technique other than EELS. By performing line scans, it was possible to quantify all the detected elements (B, C, N) as a function of the probe position. From the atomic ratios and the shape of the atomic distribution, Suenaga et a . [16] demonstrated that this particular nanotube was made of a succession of 3 carbon layers, 6 boron nitride layers and finally 5 carbon layers. 

Figure 11.9. Contrast formation in cryo-TEM. (a) Schematic image of a vesicle formed with phospholipid molecules, (b) Schematic representation of a phospholipid molecule with polar headgroup and apolar tail. (c)(d) Projection of the polar head group, which is the strongest scattering center, (e) Calculated line scan considering the projection of the polar head groups, (d) Schematic image of a vesicle. (e)(f) Experimental images of vesicles where the double layer with a thickness of about 3.5 nm is clearly seen. Adapted from Sagalowicz et al. 2003.

The synthesized TiBj-Cu FGM samples were longitudinally cut, polished and observed with SEM. The distributions of element Ti and Cu were line-scanned and area-scanned with EDX. The densities of layers were measured with image-analysis method. 

FIG. 2 Reduced positive feedback over a conducting support covered by a layer of biomolecules or other organic surfactants. The example shows a line scan above a glassy carbon electrode which was covered by a layer of adsorbed ubiquinone-10 at the location (135 < i/fim < 210). Experimental parameters ET = +660 mV (SCE), Es = —250 mV (SCE), a = 5 fim, vt = 7 /r,m s 1, solution 2 mM ferrocene mono-carboxylic acid, 0.1 M KC1, 0.1 M phosphate buffer, pH 7.4 (From G. Wittstock, unpublished, 1996.)... 

Initial studies were carried out on type 304L stainless steel surfaces, effectively biased at +0.430 V versus SCE in a solution containing 0.3 mol dm-3 NaC104 and 0.3 mol dnT3 NaCl. Figure 43 shows typical current fluctuations, which were observed as the tip was scanned over the surface. The current spikes, of the order of 100 pA, were heterogeneously distributed across the surface, typically with a duration less than the time taken for the tip to complete a line scan (0.25 s). As the passive layer thickened with time, the number of fluctuations decreased. 

WS used layer-line scans and computer curve resolution to find 34 measurable spots on a flat film ( ). No meridional data were quantified. (1979) The Lp corrections of Celia, Lee and Hughes (24) were used. 

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