Microscopic and Spectroscopic Characterization of Stacking‐Sequence Disordered SiC

Nanometric silicon carbide ( SiC ) powder (~5 nm) with a stacking‐sequence disordered structure ( SD ‐ SiC ), synthesized from elemental powders of Si and C, was investigated by microscopic and several spectroscopic methods. The structure of SD ‐ SiC was characterized by transmission electron microscopy ( TEM ), 13 C , and 29 Si ‐ NMR , and by infrared ( IR ), Raman, and X‐ray photoelectron spectroscopy ( XPS ) methods. TEM characterizations showed relatively large deviations of the lattice parameters in the as‐synthesized SiC, indicative of the presence of stacking‐sequence disorder. IR analysis showed a weaker Si ‐ C bond in the SD ‐SiC than in the 3 C ‐ SiC . XPS determinations showed that C and Si in SD ‐ SiC are similar to those in 3 C ‐ SiC . Broader peaks of 29 Si and 13 C MAS ‐ NMR also indicate that the structure of SD ‐ SiC is different from that of 3 C ‐ SiC . Raman spectroscopy exhibited activities for the crystalline polytypes and the amorphous of SiC but lack of them for the SD ‐ SiC . The inactivity of Raman spectroscopy for the SD ‐ SiC along with large deviation of the lattice constant and the extremely broad X‐ray diffraction peaks would indicate that SD ‐SiC is a possible intermediate state between conventional polytype SiC and amorphous SiC , that is, a possible new type of SiC .