The melting line of graphite and the electrical resistivity of liquid carbon are investigated along the melting line by a flash-heating experiment under high pressures. The melting temperature of graphite increased from 4650 K at 1.4 GPa to a maximum of 4790 K at 5.6 GPa, then decreased to 4640 K at 9.4 GPa. The electrical resistivity of liquid carbon along the melting line decreased from 900 to $600\mu \Omega \mathrm{cm}$ with an increase of pressure of 1.4 to 9.4 GPa. Changes in slopes of the melting line and of the electrical resistivity at about 5.6 GPa suggest a possibility for a first-order phase transition in liquid carbon.

• Received 8 August 1996

DOI:https://doi.org/10.1103/PhysRevLett.79.2474