Single axis diffraction

Is a zone axis of a single crystal diffraction pattern exactly parallel to the transmitted beam Explain your answer graphically. 

When regarding rotation around a single axis, an experimental set-up most commonly used in two-dimensional powder diffraction, the function reduces to ... 

Recently single crystal diffraction studies of Ero.75Luo.25 (Habenschuss et al., 1973) and Hoo.oScoi (Felcher et al., 1976) have been performed. In the case of Ero.75Luo.25, structures identical to those of the high and intermediate temperature phases of Er were observed but with the c-axis ordering temperature Tn lowered... 

The examples in Figure 3 illustrate these possibilities. Figure 3a shows a diffraction pattern from a single crystal Fe thin film, oriented with the [001] crystal axis... 

A diffraction pattern of a single MWCNT (Fig. 1) contains in general two types of reflexions (i) a row of sharp oo.l (/ = even) reflexions perpendicular to the direction of the tube axis, (ii) graphite-like reflexions of the type ho.o (and hh.o) which are situated in most cases on somewhat deformed hexagons inscribed in circles with radii gho.o (or hh.o)-... 

Small needle-shaped single crystals were examined by transmission electron microscopy (TEM) and electron diffraction (ED) (see Fig. 16-17). The results show that the crystals are elongated along the b-axis, which is the direction of weak intermolecular n-n interactions, and have a well-developed (ab) top surface. It corresponds to the surface of aliphatic tails (direction of weak intermolecular interactions). There are indications of displacement of successive ( / )-laycrs along the fl-axis, in line with the other signs of disorder in the aliphatic layer. 

Figure 16-17. Left transmission electron micrograph of small single crystals of Ooct-OPV5 scale bar 5 pnt. The arrows indicate the 6-axis direction. Right electron diffraction pattern of the same single crystals. The arrow indicates the 613 relteclion spot (crysial dimensions 5x40 pm2 Philips STiiM CM 12 operated at 120 kV. lnslilul Charles Sudron, Strasbourg).

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