High-pressure melting curves of the transition metals Cu, Ni, Pd, and Pt

Melting curves of Cu, Ni, Pd, and Pt were measured in a laser-heated diamond-anvil cell up to 43, 52, 28, and 28 GPa, respectively. The obtained results are compared with previous studies. In particular, the measurements made in Cu are in agreement with the literature. In Pt the experiments are consistent with Z method calculations indicating that earlier measurements probably underestimate the melting temperature of Pt at high pressure. Cu, Pd, and Pt show a qualitative similar melting behavior. In the case of Ni, experiments confirm that it has a low melting slope of 28 K/GPa. Ni is the only transition metal of groups 10 and 11 of the Periodic Table that shows such a slope since the other metals have a steeper melting slope of 41-47 K/GPa. The determined melting curves can be described with Simon equations which are reported. The present results increase the database on high-pressure melting and could contribute to improving the understanding of this phenomenon. DOI: 10.1103/PhysRevB.87.054108