Microscopy from Scientific Research

DF-TEM of an APT needle showing the grain boundary configuration. The crystal orientation of the two grains is identified via the selected-area electron diffraction patterns in (B) and (C), with the viewing direction oriented to keep grain 2 on the (100) zone axis and the 2D projected polarization directions drawn in with white arrows. The resulting change in c-axis orientation across the grain boundary is about 76, corresponding to a bound charge |ρ| = 3.9 ± 0.4 C cm-2. For the DF-TEM image in (A), the 002 reflection in (C) was used.

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