Surface topography, development

Ge at 8.3 and 6.8 eV, respectively, the ion-bombarded area was quite uniform, but as Buo decreased, more surface topography developed. Their SEM images of Si, Ge, Sn, and A1 after sputtering with 20 keV 02+ are shown in Fig. 4.22. Rotation of the sample (sometimes called Zalar rotation) [79] is commonly used with off normal incidence sputtering to minimize the formation of sputter-induced topography. 

Netcheva, S., Bertrand, P. (1999) Surface topography development of thin polystyrene films under low energy ion irradiation. Nucl. Instr. and Meth. in Phys. Res. B,151, 129-134. 

The sputtering process is frequendy used in both the processing (e.g., ion etching) and characterization of materials. Many materials develop nonuniformities, such as cones and ridges, under ion bombardment. Polycrystalline materials, in particular, have grains and grain boundaries that can sputter at different rates. Impurities can also influence the formation of surface topography. ... 

An initially flat silicon electrode surface will develop a surface topography if the photocurrent varies locally. This variation can be caused by a lateral variation of the recombination rate or by a lateral variation of the illumination intensity. The photoelectrochemical etching of a silicon electrode is related to the etch-stop techniques discussed in Chapter 3. While different etching rates for different areas of the electrode may be obtained by electrical insulation or by a different doping density, the etch rate may also be altered by a difference in illumination intensity. Basically four photoelectrochemical etching modes are possible for homogeneously doped substrates ... 

SEM Utilizes a focused electron beam that systematically scans across the surface of a sample. It can be used to characterize the surface topography of bulk powders or pellets. Early SEM developments have been described by Von Ardenne (1938) and by Smith et al (1977). The principal high-resolution SEM imaging method is surface sensitive with an escape depth lO nm and sensitive to or... 

Presently, there appears to be two well-developed areas in the analysis of CME surface the evaluation of surface topography by SEM and the determination of elemental composition by XPS. Methodology development now needs to be directed toward those techniques that will provide molecular description of surface, especially in situ measurements during electrolyses. Of the available spectroscopic methods such as IR and Raman, the sensitivity in a reflectance mode seems to be the major problem. There is a continuing need for better approaches to quantitation of the surface concentration, spatial distribution and orientation of immobilized molecular moieties. Carbonaceous... 

The chemical organization (i.e., the primary amino acid sequence) and the folded structure (i.e., the secondary, tertiary, and quaternary structure), including the generation of a surface topography as a discrete three-dimensional object, are the essential features of a polypeptide and protein around which a high-performance separation can be designed. Two sets of factors must come into play for these separation skills to be developed. The first set... 

Recently, in the fusion experiment DIII-D a steady decrease of the spectroscopic CD signal, representative for chemically eroded species, was observed over the course of several years [60], After the use of the same tiles for 10 years in divertor application the CD band virtually disappeared. As possible reasons the frequent boronizations and the development of surface topography were discussed. As surface analysis of the tiles used in DIII-D did not show any significant traces of impurities, also the assumption of a reduction due to impurities was ruled out [61]. 

At high ion fluences the chemical erosion yield appears to decrease. This fluence dependence may originate from the development of a pronounced surface topography. Dedicated investigations are needed in plasma simulators where high fluences can be achieved. 

The STM was the first scanning probe microscope to be developed [1]. Although the original aim was to image the surface topography of metals on the atomic scale and in... 

Surface representations. Often, the interactions between macromolecules take place exclusively at their surfaces. Surface representations have been developed to better visualize macromolecular surfaces. These representations display the overall shapes of macromolecules and can be shaded or colored to indicate particular features such as surface topography or the distribution of electric charges. 

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