By means of their investigations, Wieligor and coworkers noted that "For small size crystals the TO peak is accompanied by a shoulder on the low frequency side. For SiC of average grain sizes of 400 and 220 nm the shoulder was observed at 765.5 cm -1 . For 20 nm crystals it was observed at 761.5 cm -1 and for NW-B [sample] at 757 cm -1 . … Recently, showed that the separation between the TO peak and the shoulder reflects the average distance between stacking faults" .