The origin of polytype structures

Silicon carbide (SiC) micro bullets were grown on a bio-carbon based charcoal substrate, the morphology and crystal structure were analyzed. In order to collect the crystallographic details scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM/TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) were used. For this a thin lamella from the SiC micro bullet was extracted by focused ion beam (FIB). Electron microscopy revealed that the SiC micro bullets had a high density of stacking faults along their growth direction. However, the size and morphology of the micro bullets were relatively homogeneous, despite the high stacking fault density, i.e. the growth was quite robust at the synthesis temperature (1750 °C). The findings open up to SiC ceramics from bio-carbon with anisotropic porosity for the development of novel light weight high temperature resistant materials.