Ultra-long Si3N4 nanobelts prepared by nanosilicon, nanosilica and graphite

The composition and morphology of obtained products depended on the processing atmosphere using the raw materials of nanosilicon, nanosilica and graphite, with N2-generating several millimeters long single-crystal Si3N4 nanobelts (NBs) and Ar SiC nanobelts. The width and thickness of in situ NBs ranged from 100 to 300 nm and 50-100 nm with an average width of 196 nm, while the width and thickness of ex situ NBs fluctuated from 150 to 500 nm and 80-200 nm with an average width of 436 nm. Alumina-assisted VS mechanism was proposed for the growth mode of in situ growth of Si3N4 nanobelts, while a combined mechanism involving VS and VLS was controlled the growth of Si3N4 nanobelts obtained on the inner walls of the crucible due to the presence of Fe2O3, which provides an effective means of fabricating ultra-long Si3N4 nanobelts on an industrial scale.