Abstract
The high-pressure/high-temperature behavior of boron has been investigated up to 30 GPa using x-ray diffraction techniques. We have investigated the isothermal compressibility of rhombohedral-105 (formula presented) boron to 30.7 GPa, and determined the bulk modulus (formula presented) to be (formula presented) with (formula presented) We found that the a direction of (formula presented) boron (hexagonal setting) is less compressible than c, which indicates that the B10-B-B10 chain is less rigid than the (formula presented) cluster. High P-T studies were conducted using double-sided laser heating to temperatures of 3500 K. (formula presented) boron transforms above 10 GPa at high temperature to a tetragonal phase that remains on P-T quenching. The transformation results in both a higher density and higher entropy phase and is consistent with the formation of the (formula presented) phase of boron.
Original language | English |
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Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 67 |
Issue number | 17 |
DOIs | |
State | Published - May 30 2003 |