Line profiles

Figure C3.3.6. Doppler-line profiles for molecules scattered into the CO COO O J= 72) state by collisions with hot methylpyrazine molecules as depicted by the equations above each half of the figure. The energy of methylpyrazine...

Fig. 2.43. EFTEM images and corresponding line profiles of oxidized AIAs/(AI,Ga)As multilayers.

An example of interface analysis by EDXS line profiling at high lateral resolution is given in Eig. 4.29. It is of particular importance, because the distribution of light elements like carbon, nitrogen, and oxygen is also revealed. This was possible by means of an Si (Li) EDXS detector (Kevex) with an ultrathin window attached to a dedicated STEM HB 501, from Vacuum Generators, with a cold field-emission cathode. 

Fig. 4.29. EDXS line-profile analysis across the interfacial region of a C-fiber reinforced SiC composite and corresponding TEM bright-field image.

FIGURE 21.17 The comparison of line profiles along solid lines shown in each image of Figures 21.16 and 21.17. (a) Apparent and (h) the corresponding real height profiles. 

When applied to the XRD patterns of Fig. 4.5, average diameters of 4.2 and 2.5 nm are found for the catalysts with 2.4 and 1.1 wt% Pd, respectively. X-ray line broadening provides a quick but not always reliable estimate of the particle size. Better procedures to determine particle sizes from X-ray diffraction are based on line-profile analysis with Fourier transform methods. 

Figure 3.6 A comparison of an experimentally obtained STM image and line profile (f) with those calculated15 from different Si(l 11)7x7 models. In the line profiles underneath the image the dotted lines are the experimentally obtained data from (f) and the solid lines are the equivalent profiles from different structural models (a) Binnig et al. 3 (b) Chadi 44 (c) Snyder 45 (d) McRae and Petroff 46 and (e) Takayanagi et al.47 Very good agreement is obtained with Takayanagi et al. s model. (Adapted from Tromp et al.15).

Line profiles of these structures indicate a step-height of between 0.14 and 0.15 nm for the overlapping Mg(0001)-0-Mg bilayer (Figure 4.9). Clearly, at... 

Figure 4.10 With increasing oxygen exposure at 295 K, the Mg(0001) surface consists of both hexagonal and square lattice structures the line profiles indicate repeat distances of 0.321 and 0.56 nm in the atom resolved hexagonal and square structures, respectively, the former being the most prevalent structure present. (Reproduced from Ref. 41).

A line profile analysis of the saturated acetylide surface reveals the buckled nature of the overlayer with a periodicity of seven protrusions or 14 lattice units along the < 110 > axis. The nominal 14 units actually match 13 lattice units therefore to accommodate seven protrusions on 13 lattice units with equal spacing would result in surface buckling (Figure 5.13). The distance between two terminal silver atoms is 5.37 A, which is 2% shorter than that in silver acetylide based on the assumption of covalent radii. 

L oxygen exposure with a (2 x 1) structure present image (b) is after 42 L oxygen exposure with both (2 x 1) and (3 x 1) states present line profiles of the rows running in the < 100 > direction also shown, inter-row spacings are twice and three times the Cu-Cu distance in the < 110 > direction (c). Also shown is the image of a c(6 x 2) structure present as a minor component (b, d). (Reproduced from Ref. 16). 

K well-ordered chains running in the < 110 > direction separated by the atom resolved structure of the Cu(l 10) surface with a spacing between the rows of 0.36 nm (see line profile), (b) The spacing within the chains is 0.51 nm (see line profile), i.e. close to twice the Cu-Cu distance within the copper rows running in the < 110 > direction. (Reproduced from Refs. 16, 18). 

Figure 10.7 Constant-height STM images and line profiles of a partially sulfided Ni(100) surface before (a) and after (b-e) exposure to different alcohols (a) 0.23 ML sulfur (b) CH3OH (c) CH3CH2OH (d) CH3CH2CH2OH (e) C6H5OH. (Reproduced from Ref. 28).

Figure 5.24(B) shows a line profile extracted from the map of Figure 5.24(A) by averaging over 30 pixels parallel to the boundary direction corresponding to an actual distance of about 20 nm. The analytical resolution was 4 nm, and the error bars (95% confidence) were calculated from the total Cu X-ray peak intensities (after background subtraction) associated with each data point in the profile (the error associated with A1 counting statistics was assumed to be negligible). It is clear that these mapping parameters are not suitable for measurement of large numbers of boundaries, since typically only one boundary can be included in the field of view.

Magnification 2 MX. Composition range is shown on the intensity scale at RHS (Reproduced with permission by Carpenter et al. 1999). (B) Line profile extracted from Figure 5.24a averaged over 30 pixels parallel to the boundary. The solid curve is a Gaussian distribution fitted to the data (Reproduced with... 

Figure 5.25. (A) Quantitative Cu map of an Al-4wt% Cu film at 230 kX, 128 x 128 pixels, probe size 2.7nm, probe current 1.9 nA, dwell time 120 msec per pixel, frame time 0.75 hr. Composition range is shown on the intensity scale (Reproduced with permission by Carpenter et al. 1999). (B) Line profile extracted from the edge-on boundary marked in Figure 5.25a, averaged over 20 pixels ( 55 nm) parallel to the boundary, showing an analytical resolution of 8nm FWTM. Error bars represent 95% confidence, and solid curve is a Gaussian distribution fitted to the data (Reproduced with permission by Carpenter...

Figure 2.8 Line profiles of the alumina film on Ni3AI(l 1 1) for different sample bias voltages [36],...

Figure 4.12 Left experimental line profile for Ti02(l 1 0) along [1 1 0] in the presence of pristine defects (Ovac, OHbr) and undissociated water molecule for V= 1.5 V, / = 0.08 nA (80 K). Right calculated density contour (top, 1.5 V,...

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