Automated crystal orientation and phase mapping of iron-oxide nanocrystals in a transmission electron microscope

For nanocrystal sizes of below about 50 nm, the intensities of these reflections are nearly kinematical (i.e. proportional to the square of the structure factors). Such precession electron diffraction patterns are, therefore, very useful for structural fingerprinting of nanocrystals in a TEM. This paper illustrates the application of this technique to a mixture of iron oxide nano-crystals of magnetite (Fe₃O₄, Fd3m, a = 0.83 nm) and maghemite (gamma-Fe₂O₃, P4,32, a = 0.83 nm).