Abstract
We synthesized and solved an unexpectedly complex crystal structure of CaB 6 under high pressures (up to 44 GPa) and temperatures. The only known crystal structure in the large family of metal hexaborides, a simple cubic cP7 type discovered over 80 years ago, is shown here to transform into a tetragonal tI56 configuration comprised of unfamiliar 24-atom boron units. The interpretation of the convoluted x-ray diffraction pattern was accomplished with an ab initio evolutionary search which identified the tI56 structure (28 atoms per primitive unit cell) without any parameter input. The exotic CaB 6 phase was successfully quenched down to ambient pressure.
Original language | English |
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Article number | 075501 |
Journal | Physical Review Letters |
Volume | 109 |
Issue number | 7 |
DOIs | |
Publication status | Published - Aug 16 2012 |
ASJC Scopus subject areas
- Physics and Astronomy(all)