Phase diagram for mercury up to 67 GPa and 500 K

The pressure-temperature phase diagram for mercury is determined using energy-dispersive x-ray diffraction and a diamond anvil cell. In addition to the well-known structures of Hg, one new modification was found to be stable in the present experimental region. An orthorhombic lattice with four atoms in the unit cell represents all the experimental data for this new phase. The locations of the phase boundaries between the different phases α-β-γ-δ are determined for the extended p-T region. Furthermore, the parameters of the equations of state of the different phases are evaluated