Topography contrast

Fig. 35 Simultaneously measured a,b topography c,d repulsive force e,f a.c. current amplitude on graphite before (a, c, e) and after (b, d, f) Fourier space filtering. The Fourier transform parameters for the inverse transformation of b are taken from the Fourier transformation of e. Scan width 5.5 nm, 500x500 pixel, scan speed 50 nm/s, repulsive force 100 nN, a.c. excitation 3.9 mV at 102 kHz. In order to minimise the piezo amplifier noise, a weak feedback was used and the topography contrast is smaller than 100 pm. Force contrast 1 nN, current contrast from 5.5 to 7 nA...

Fig. 40 Conducting film, plasma polymerised from 2-iodothiophene, on silicon. Left topography contrast (shaded pseudo-3D-image) with 405 nm corrugation. Middle real part (conductivity), with a contrast of 2.8 nA. Right imaginary part (capacity), with a contrast of 270 pA, the a.c. currents shown in the middle and in the right image were simultaneously measured together with the topography. The cantilever is made of silicon nitride coated with gold. The excitation is 0.8 V at 60 kHz, the scan speed is 4.17 pm/s...

Fig. 41 Barium tetratitanate ceramics, partially reduced. The excitation is 5 V at 666.6 Hz, the scan speed 323 nm/s. Left topography contrast with 4.8 nm corrugation. Middle ohmic current, with a contrast of 170 pA inset 120 pA). Right capacitive current with a contrast of 310 pA inset 810 pA)...

Fig. 45 Polypropylene film, contaminated with two different organic substances. Left topography contrast with 8.1 nm corrugation (shaded). Right surface charge contrast (a.u.)...

The yield of reflected BSEs increases with increasing atomic number. Elements having higher atomic number offer a higher probability of backscattered elements, including an additional atomic number contrast ( material contrasf) to the surface topography contrast (Fig. 3.6). 

In contrast to AFM, which directly provides accurate height mfonnation in a limited range, quantitative assessment of the surface topography by SEM is possible by measuring die parallax of stereo pairs [45]. 

Figure Bl.19.24. Friction loop and topography on a heterogeneous stepped surface. Terraces (2) and (3) are composed of different materials. In regions (1) and (4), the cantilever sticks to the sample surface because of static friction The sliding friction is tj on part (2) and on part 3. In a torsional force image, the contrast difference is caused by the relative sliding friction, Morphological effects may be...

The province s climate is defined as subtropical mountainous with a dry season. However, the topography does allow the development of contrasting environments. Thus, the moist winds from the southeast enter the province and release their moisture from submountainous ranges... 

Fig. 3 shows a topographic image of a Pt/y-A s catalyst. Contrast from particles is clearly separated from the substrate topography. On the other hand pores on the substrate are well defined. If the aperture includes some portion of the dark field spot then the resolution for small particles is improved. Fig. 4 shows an image of a 100% dispersed catalyst (as measur ed by chemisorption methods) in which particles of about 5 A can be seen. 

Atomic force microscopy (AFM) is a commonly employed imaging technique for the characterization of the topography of material surfaces. In contrast to other microscopy techniques (e.g., scanning electron microscopy), AFM provides additional quantitative surface depth information and therefore yields a 3D profile of the material surface. AFM is routinely applied for the nanoscale surface characterization of materials and has been previously applied to determine surface heterogeneity of alkylsilane thin films prepared on planar surfaces [74,75,138]. 

FIGURE 5.22 (See color insert following page 280.) Perspective four-cell view snapshots of various stationary-phase models, which illustrate the contrasting surface topography with bonding density and alkyl chain length. (Adapted from Lippa, K.A., et al., Anal. Chem., 11, 7852, 2005.)... 

In this chapter we discuss double-crystal topography, in which we obtain a map of the diffracting power of a crystal compared to that of a reference. We first treat the principles and geometries, the mechanisms of image contrast and resolution and the ttse of laboratory and synchrotron radiation. We then discuss applicatiorrs wafer inspection, strain contour mapping, topography of curved crystals. 

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