A cubic silicon nitride embedded in amorphous SiO2 compound has been charac
terized by means of high-resolution analytical electron microscopy. The spe
cimen was prepared from beta -Si3N4 powders at a high pressure and temperat
ure by shock wave compression. The typical high-resolution electron microsc
opy image from one small crystallite together with its diffractodiagram pat
tern indicated that the Si3N4 crystallites had a cubic symmetry. The electr
on energy loss spectrum from the small crystallite is very different from t
hose of outside amorphous SiO2 phase and raw beta -Si3N4 particles, and the
re are more N elements that were detected in this small crystallite than th
ose in standard Si3N4.