Phys.org March 18, 2024
Despite several experimental attempts, synthesis, and recovery of the theoretically predicted post-diamond BC8 phase remains elusive. Through quantum-accurate multimillion atom molecular dynamics (MD) simulations, an international team of researchers (USA – University of South Florida, Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sweden) uncovered the extreme metastability of diamond at very high pressures, significantly exceeding its range of thermodynamic stability. They predicted the post-diamond BC8 phase to be experimentally accessible only within a narrow high pressure–temperature region of the carbon phase diagram. The diamond to BC8 transformation proceeded through premelting followed by BC8 nucleation and growth in the metastable carbon liquid. The team proposed a double-shock compression pathway for BC8 synthesis, which is currently being explored in experiments at the National Ignition Facility… read more. TECHNICAL ARTICLE
jGraphical abstract. Credit: J. Phys. Chem. Lett. 2024, 15, 4, 1152–1160, January 25, 2024Â