Melting of Fe3C under laser-shock compression to 300 GPa

We directly measure melting of shock compressed Fe3C to 300 GPa using in situ x-ray diffraction. We find melting begins at a shock stress state near 150 GPa and is fully liquid by 190(10) GPa. We find no evidence for crystalline Fe7C3, which is the incongruent melting phase observed in static compression experiments. These observations indicate that the equilibrium melting reaction of Fe3C to liquid and Fe7C3 is kinetically inhibited on nanosecond timescales.