Datensatz

Zusammenfassung

Transmission electron microscopy (TEM) is an ideal tool for characterizing materials in terms of chemical composition, micro- and nanostructure as well as crystal structure up to atomic level. The major advantage of TEMis superior spatial resolution. It is possible to obtain chemical composition and structure information from even nm-sized crystals and that allows unambiguous identification of the phases present in a TEM sample. Chemical information is supplied by EDX analysis, electron energy-loss spectroscopy (EELS) and to a small extent by Z-contrast imaging (high-angle annular dark-field imaging – HAADF). Micro- and nanostructure information is provided applying brightfield and dark-field imaging based on diffraction contrast and high-resolution imaging (HREM). Structure information is obtained from selected area electron diffraction (SAED), convergent beam electron diffraction on nm-sized crystals, precession electron diffraction which allows crystal-structure determination and fast Fourier transforms (calculated diffraction-pattern FFT) from high-resolution images.