FCC–HCP phase boundary in lead

The pressure–temperature phase diagram of Pb was mapped from synchrotron X-ray diffraction data measured to 40 GPa and 800 K, in the region including the hexagonal-close-packed to face-centered cubic transformation; the corresponding p–T–V equations of state were fitted for both phases. An unexpected interaction of Pb with NaCl surrounded the samples and significant reduction of the alloying temperature with Au was observed.