Temperature-pressure phase diagram of cubic Laves phase Au2Pb

The temperature (T) as a function of pressure (P) phase diagram is reported for the cubic Laves phase compound Au2Pb, which was recently proposed to support linearly dispersing topological bands, together with conventional quadratic bands. At ambient pressure, Au2Pb exhibits several structural phase transitions at T-1 = 97 K, T-2 = 51 K, and T-3 = 40 K with superconductivity below T-c = 1.2 K. Applied pressure results in a rich phase diagram where T-1, T-2, and T-3 evolve strongly with P and a possible new phase is stabilized for P > 0.64 GPa that also supports superconductivity below 1.1 K. These observations suggest that Au2Pb is an ideal system in which to investigate the relationship between structural degrees of freedom, band topology, and resulting anomalous behaviors.