Vapour growth of boron crystals

Synthesis of α- and β-Rhombohedral Boron Powders via Gas Phase Thermal Dissociation of Boron Trichloride by Hydrogen

“…The parameters of the BCl 3 / H 2 molar ratio and reaction temperature were investigated. The original aspect of this study is that the substrate material is different from other studies in the reported literature [13][14][15][16][17] ; hence, the problem of surface/ powder separation is avoided. Using the original experimental setup, a-and b-rhombohedral boron can be synthesized at low temperatures using a one-stage process.…”

“…[5,10,11] Investigations on high-temperature gas-phase reduction of boron compounds generally include the deposition of high-purity elemental boron on metallic surfaces by passing borane gases or boron compound/H 2 gas mixtures through the hot surfaces at temperatures between 998 K and 1873 K (725°C and 1600°C). [12][13][14][15][16][17] The most stable polymorph of boron is b-rhombohedral and higher reaction temperatures in this process provide the formation of this high-temperature crystalline phase. [18] However, a reaction between the boron and the reactor materials of construction causes a separation problem between the reactor surface and the powder.…”