title: Stabilization of boron carbide via silicon doping.
abstract: Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in the material, and this raises the possibility of doping the boron carbide to eliminate this polytype. In this work, we have synthesized boron carbide doped with silicon. We have conducted a series of characterizations (transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and x-ray diffraction) on pure and silicon-doped boron carbide following static compression to 50 GPa non-hydrostatic pressure. We find that the level of amorphization under static non-hydrostatic pressure is drastically reduced by the silicon doping.
authors.affiliation: Department of Physics and Mathematics, University of Hull, Hull HU6 7RX,UK. Joule Physics Laboratory, School of Computing, Science and Engineering, University of Salford, Manchester M5 4WT, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Proctor
authors.forename: V
authors.initials: V
authors.lastname: Bhakhri
authors.forename: R
authors.initials: R
authors.lastname: Hao
authors.forename: T J
authors.initials: TJ
authors.lastname: Prior
authors.forename: T
authors.initials: T
authors.lastname: Scheler
authors.forename: E
authors.initials: E
authors.lastname: Gregoryanz
authors.forename: M
authors.initials: M
authors.lastname: Chhowalla
authors.forename: F
authors.initials: F
authors.lastname: Giulani