Tuesday, February 19, 2013

1302.4236 (Oleksandr O. Kurakevych et al.)

Crystal structure of dense pseudo-cubic boron allotrope, pc-B52, by
powder X-ray diffraction
   [PDF]

Oleksandr O. Kurakevych, Vladimir L. Solozhenko
During past years, a number of reports have been published on synthesis of tetragonal allotrope of boron, t-B52 phase. However, no unambiguous characterization of the crystal structure has been performed to the present time, while remarkable variation of the a/c lattice-parameter ratio raises strong doubts about its uniqueness. Here the Rietveld refinement of the crystal structure of the high pressure - high temperature boron phase synthesized by a direct solid-state transformation of rhombohedral beta-B106 at 20 GPa and 2500 K has been reported for the first time. Although this boron allotrope belongs to the t-B52 type, its structure can be considered as pseudo-cubic with the a/c ratio of sqr(2).
View original: http://arxiv.org/abs/1302.4236

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