Researchers from the University of Oxford and Diamond Light Source have discovered a new material, a Calcium hexaboride (CaB6) compound crystallising in a previously unknown crystal structure. Published in Physical Review Letters these findings can pave the way to customised boron-based intermetallics. The ordinary CaB6 is a semiconductor with an amazing hardness and high melting temperature governed by a high chemical stability. It has been investigated for a long time due to its relevance for many industrial productions processes, like the manufacturing of boron-alloyed ultrahigh-strength steels.
The Oxford team - a collaboration between a group from the Department of Materials and a group from Earth Sciences - achieved these results by imposing high pressure up to 44 GPa and laser heating up to 2.000 K on a ‘normal’ CaB6 crystal. In doing so they created this novel substance which probably has metallic properties. The measurements were taken at Diamond’s Extreme Conditions beamline, I15, which is specially suited for such studies of material properties under extreme conditions.
Image to the right: Figure 1, The known cubic structure of CaB6 is made out of boron octahedron
Pressure-Driven Evolution of the Covalent Network in CaB6
A. N. Kolmogorov, S. Shah, E. R. Margine, A. K. Kleppe, and A. P. Jephcoat
Physical Review Letters Volume 109, Issue 7 (2012)
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