The use of electron diffraction to solve crystallographic
problems was pioneered in the Soviet Union by
B. K. Vainshtein and his colleagues as early as the 1940s
[1]. In the elektronograf, magnetic lenses were used to
focus 50 keV to 100 keV electrons to obtain diffraction
with scattering angles up to 3 to 5 and numerous
structures of organic and inorganic substances were
solved. The elektronograf is very similar to a modern
transmission electron microscope (TEM), in which the
scattered transmitted beams can be also recombined to
form an image. As the result of numerous advances in
optics and microscope design, modern TEMs are capable
of a resolution of 1.65 Å for 300 kV (and below 1 Å
for 1000 kV) electron energy-loss combined with chemical
analysis (through x-ray energy and electron-loss
energy spectroscopy) and a bright coherent field emission
source of electrons.
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