Melting curve of face-centred-cubic nickel from first principles calculations

Abstract

The melting curve of Ni up to 100 GPa has been calculated using first principles methods based on density functional theory (DFT). We used two complementary approaches: i) coexistence simulations with a reference system and then free energy corrections between DFT and the reference system, and ii) direct DFT coexistence using simulation cells including 1000 atoms. The calculated zero pressure melting temperature is slightly underestimated at $1637 \pm 10$ K (experimental value is 1728 K), and at high pressure is significantly higher than recent measurements in diamond anvil cell experiments [Phys. Rev. B {\bf 87}, 054108 (2013)]. The zero pressure DFT melting slope is calculated to be $30 \pm 2$ K, in good agreement with the experimental value of 28 K.