Small angle diffraction pattern, silicon

Cilas 1064 has high resolution, giving information over the size range 0.04 to 500 pm for suspensions and 0.3 to 500 pm for dry powders in one shot, due to a double sequenced laser system (two lasers at different incident angles) and 64 separate silicon detectors to give 100 size channels of data. The benefits of such a system include coverage of a wide size range with a small optical bench structure. The diffraction pattern is compared to a known powder and the size distribution calculated. 

The quality, perfection, and stability of the layered assemblies and details of their internal architecture can be analyzed by a combination of different methods such as X-ray diffraction, spectroscopic (IR, UV/Vis, Raman) techniques, wave-guide spectroscopy and so on [74]. As an example. Figure 9.5 shows the small-angle X-ray diffraction pattern obtained at a grazing incident from an assembly of 28 copoly(glutamate) layers on a silicon wafer [82,83]. The insert represents a molecular picture of the assembly with only two of the 28 layers drawn. 

Microstructure of Chemical Vapour Deposition SiC Figure 6.8 shows the X-ray diffraction (XRD) patterns of CVD SiC deposited in a temperature range of 1000 to 1300°C. Detailed analyses of the X-ray results indicate that the deposits are pure silicon carbide mainly composed of //-SiC (cubic 3C crystal structure) with a small amount of er-SiC (hexagonal 4H crystal structure). It is clear from the figure that the diffraction angles of 35.6°, 41.3°, 60.1°, 72.1° and 75.5° correspond to //-SiC and the diffraction angle of 33.7° corresponds to er-SiC. As the deposition temperatures decrease, the deposits become poorly crystallised because the diffraction peaks become broader or its intensity shown in Y axis become lower. At the deposition temperature of 1000°C, the deposits are in a quasi-amorphous state. 

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