Transmission Electron Microscopy (TEM) is a vital characterization tool for directly imaging nanomaterials to obtain quantitative measures of particle and/or grain size, size distribution, and morphology.
TEM images the transmission of a focused beam of electrons through a sample, forming an image in an analogous way to a light microscope (Figure 1). However, because electrons are used rather than light to illuminate the sample, TEM imaging has significantly higher resolution (by a factor of about 1000!) than light-based imaging techniques. Amplitude and phase variations in the transmitted beam provide imaging contrast that is a function of the sample thickness (the
amount of material that the electron beam must pass through) and the sample material (heavier atoms scatter more electrons and therefore have a smaller electron mean free path than lighter atoms).
