High-resolution transmission electron microscopy: the ultimate nanoanalytical technique

摘要: To be able to determine the elemental composition and morphology of individual nanoparticles consisting no more than a dozen or so atoms that weigh few zeptograms (10−21 g) is but one attainments modern electron microscopy. With slightly larger specimens (embracing unit cells structure) their symmetry, crystallographic phase, unit-cell dimension, chemical often valence state (from parallel spectroscopic measurements) constituent may also determined using scanning beam electrons ca. 0.5 nm diameter. Nowadays crystallography, which treats digital data diffraction (ED) high-resolution transmission microscope (HRTEM) images minute (ca. 10−18g) in quantitatively rigorous manner, solves hitherto unknown structures just as X-ray does with bulk single crystals. In addition, tomography (see cover photograph its animation) enables three-dimensional picture internal structure objects, such nanocatalysts pore, well structural faults micro-fissures, constructed resolution 1 from an angular series two-dimensional (projected) images. Very recently (since this article was first written) new meaning has been given crystallography result spatio-temporal surface phenomena achieved on femtosecond timescale.