Materials Problems and Approaches for TEM and TEM/STEM Analyses - Sample Preparation Topic for Transmission Electron Microscopy - page 61

What must be kept in mind is that because of the various imaging and diffraction
modes, transmission electron microscopy is the domain of structural characteriza-
tion of multiphase materials whose phase size can range from the micron to the
sub-nanometer. TEM analyses can be carried out down to the atomic and molecular
scales. Table 4.2 shows the scales of the various analyses.
Table 4.2 Scales of the various TEM analyses
3 Approach for Beginning the Investigation of a Material
Microstructure identification and characterization are indispensable to understand-
ing the elemental mechanisms governing, for example, the behavior of a material
under various stresses. Understanding the structure-properties relations generally
requires knowledge of the material's structural components and/or its defects at all
scales, ranging from dimensions down to the atomic scale (Table 4.2) . In practice,
depending on the problem to be dealt with, a narrower range of observation scales
may suffice, but it should never be reduced to just a single dimension. Therefore, the
first step is to precisely define the problem and the level of observation scale neces-
sary for characterization. The investigation of a material using transmission electron
microscopy involves bringing together bibliographic data combining the material's
overall characteristics. It is helpful to know the material's history (processing,