A fast-pyrolysis self-propagating high temperature synthesis route to single phase of boron carbide ultrafine powders

Single phase of boron carbide B13C2 ultrafine powders was synthesized by a fast-pyrolysis-self-propagating high temperature synthesis method. The X-ray diffractometry is demonstrated a pure phase of rhombohedral structure. The field-emission scanning electron microscopy and transmission electron microscopy show that the size of particles ranged from 50 to 200 nm, with approximately 90 nm in average. The energy dispersive X-ray spectroscopy reveals that the sample has a uniform composition with the B/C atomic ratios ranging from 6.38 to 6.49. The Raman spectrum indicates the characteristic vibrations of C–B–C chain and B12 icosahedron. Fast-pyrolysis-self-propagating high temperature synthesis and vapor–solid growth mechanism ware proposed.