In this article, we show that nanometer-sized precipitates
of atomic numbers higher than those of the surrounding crystalline
matrix can be clearly revealed in a conventional transmission
electron microscope by high-angle, centered dark-field imaging
after minimizing the diffraction contrast. The effect is similar
to that of Z-contrast STEM, albeit with a spatial resolution
limited to 1 nm. Its sensitivity to atomic number differences
between precipitates and matrix is about 10, which is demonstrated
for precipitates formed after Er, Ge, Cr, and Si ion implantation
into SiC.
