
Diamond melts under extreme pressure, defying expected phase changes
Scientists used the OMEGA laser to shock tiny diamond samples to 0.6–1.8 terapascals, heating them to about 7,300 kelvin. They observed diamond melting directly into liquid carbon without forming the predicted BC8 phase, with the crystal lattice persisting until melting and a surprising density reversal where solid diamond becomes less dense than its liquid. The findings resolve earlier temperature discrepancies, align with theory, and have implications for inertial confinement fusion models and the study of planetary interiors.











