Indexed microdiffraction patterns

Figure 6 Indexed microdifFraction patterns from some of the iron-rich second phase particles in steam treated (700 °C for 4h) FeZSM-5 grown from a stirred gel with Si02/Fe203-ratio 50.

Microdiffraction patterns are taken from individual particles after the reduction treatment and are shown in Figs. 3a-d. Most particles with platelet shape and straight edges produce similar microdiffraction patterns, one of which is shown in Fig. 3a. It is indexed as PtsSi with CusAu structure on [100] zone axis. Figs. 3b and 3c show the diffraction patterns from the not reacted Pt on [100] and [310] zone axes, respectively. Particles with irregular forms show various diffractions and a considerable amount of them can be attributed to Pt Sis. One such pattern is shown in Fig. 3d, exhibiting Pt Sis on [152] zone axis. 

Figure 3. Microdiffraction patterns from four single particles after the reduction, indexed as (a) [100] PtsSi, (b) [100] Pt, (c) [310] Pt and (d) [152] Pt Sis.

In the two cases, the antiwear films are polycrystalline, as clearly pointed out by electron diffraction patterns. Indexations of these last ones reveal that microcrystals are mainly carbonate phases, respectively strontianite and calcite. In the case of the OCABS film, electron microdiffraction patterns carried out between well-identified nanocrystallites demonstrate the existence of an amorphous phase responsible for the cohesion of the film. This phase, not identified by ATEM, probably corresponds to (amorphous) calcium oxide species recently detected by TOE SIMS analyses [46]. 

Electron Microdiffraction. Spence and Zuo, 1992. Contains well-dociunented Fortran listings for programs to simulate CBED patterns by Bloch Wave method, and multislice. Indexed patterns shown with HOLZ to speed indexing. 

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