Boron-substituted carbon powder, B x C1?x with x up to 0.17, has been successfully synthesized by hot filament chemical vapor deposition. The boron concentration in prepared B x C1?x samples can be controlled by varying the relative proportions of methane and diborane. X-ray diffraction, transmission electron microscopy, and electron energy loss spectrum confirm the successful synthesis of an amorphous BC5 compound, which consists of 10–20 nm particles with disk-like morphology. Thermogravimetry measurement shows that BC5 compound starts to oxidize approximately at 620°C and has a higher oxidation resistance than carbon.
HU QianKuWU QingHuaSUN GuangLUO XiaoGuangXU BoYU DongLiHE JuLong
We extensively explore the high-pressure structures of InBi by using a newly developed particle swarm optimization algorithm. An orthorhombic Imma structure is discovered to be stable from 43.7 GPa to 107.9 GPa, ruling out the previously speculated cubic structure. Further increasing the pressure, we find a tetragonal P4/nmm structure which is energetically more favourable from 107.9 CPa to 200 GPa. Especially, the tetragonal P4/nmm structure is known to occur at high pressure in the structures of ZnO and MgTe. We also predict this structure to be a high-pressure structure of ZnTe. Thus the tetragonal P4/nmm structure may be a universal high-pressure structure of the Ⅱ-Ⅵ and the Ⅲ-Ⅴ compounds.
