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DOE OSTI · 1771426

Phase transformation in boron under shock compression

Zhang, Shuai·Whitley, Heather D.·Ogitsu, Tadashi
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Abstract

Using first-principles molecular dynamics, we calculated the equation of state and shock Hugoniot of various boron phases. Here, we find a large mismatch between Hugoniots based on existing knowledge of the equilibrium phase diagram and those measured by shock experiments, which could be reconciled if the α-B 12 /β phases are significantly over-pressurized in boron under shock compression. Our results also indicate that there exist an anomaly and negative Clapeyron slope along the melting curve of boron at 100 GPa and 1500–3000 K. These results enable an in-depth understanding of matter under shock compression, in particular the significance of compression-rate dependence of phase transitions and kinetic effects in experimental measurements.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYDFT-MDEOSHugoniothigh pressuremeltingphase transformation

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Zhang, Shuai, Whitley, Heather D., Ogitsu, Tadashi. 2020-08-08. Phase transformation in boron under shock compression. https://doi.org/10.1016/j.solidstatesciences.2020.106376

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