Quasi in situ TEM

This so-called ex situ or quasi in situ TEM approach has allowed researchers to determine important structural information about catalysts containing, for... 

Figure 7. Schematic model based on the TEM image analysis and on in situ 7Li-NMR during galvanostatic reduction/oxidation of the carbon composite. During insertion, ionic lithium penetrates at first in the smallest interlayer spacings, then it diffuses in the slit-shaped pores where quasi-metallic clusters are formed.

In contrast to XRD methods that may introduce sample preparation artifacts (see Jiang et al. 1997 Li et al. 1998), TEM integrated with selected-area electron diffraction (SAED) and energy dispersive spectrometry (analytical electron microscopy, AEM) measurements, provides direct, in situ observations on rock microtextures, crystallite size distributions, lattice imperfections of crystallites and interstratification (see the extensive reviews by Peacor 1992 and Merriman and Peacor 1999). TEM observations on selected portions of thinned (ion-milled) whole rock samples contradict the fundamental particle theory of Nadeau et al. (1984a,b,c summarized recently by Nadeau 1998). The observations show that phyllosilicate domains with interstratified structures form coherent boundaries, and therefore, MacEwan-type crystallites do exist in quasi-undisturbed rocks (Peacor 1998). In addition, AEM studies may provide reliable mineral-chemical data on the phases devoid of any external or internal impurities. 

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