Mica, transmission electron microscopic

FIGURE 14.5 Transmission electron microscope (a) and atomic force microscope (b) images of a egates of CPPE (structure shown in right panel) on mica substrates. (Reprinted from Schnable er, H., M. Antonietti, C. Goltner, J. Hartmann, H. CoUen, P. Samori, J.P. Rabe, H. Hager, and W. Heitz /. CoUoid. Interf. Sci, 212, 24-32, 1999. With permission.)... 

The electron microprobe has been used by LeRoux et al. [1970] in the study of chemical composition of various parts of sand-size weathered micas. The scanning electron microscope is probably the most useful instrument in the study of the micromorphology of micas. Its great depth of field is a distinct advantage over the transmission electron microscope. 

The identification of size, shape, and axial ratio can also be done by direct observation in the electron microscope (EM). This is accomplished by depositing single molecules (if they can be obtained) directly on polymer-coated copper grids and then shadowing them with heavy metals or making a replica of the molecular surface on mica. The sample can then be viewed in the transmission EM and photographs can then be taken after calibration of the magnification factor. 

Fig. 1. Electron micrograph of ultrathin platinum film average platinum density 0.12 jug cm-2, deposited on mica in UHV at 275°C. Film catalyst used in reaction of n-hexane at 275°C before microscopic examination. Micrograph obtained by direct transmission through mica sliver. (X400,000).

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