Melting line and thermal equation of state of fcc-cobalt: A combined experimental and computational approach

Simone Anzellini (1) , Silvia Boccato (2) , Samuel Baty (3) , Leonid Burakovsky (3) , Daniele Antonangeli (2) , Daniel Errandonea (1) , Raffaella Torchio (4)

1 ICMUV - Institut Universitari de Ciencia dels Materials
2 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
3 LANL - Los Alamos National Laboratory
4 ESRF - European Synchrotron Radiation Facility [Grenoble]

The melting line of cobalt has been investigated both experimentally, using synchrotron X-ray diffraction coupled with laser-heated diamond anvil cells, and theoretically, using ab initio simulations. Over the investigated pressure and temperature range - between 30 and 100 GPa and from ambient temperature up to 4000 K - the hexagonal close-packed structure, stable at ambient conditions, is replaced at high temperature by the face-centred cubic structure, observed stable till melting. The melting temperatures obtained by the two methods are in remarkable agreement and the melting line can be well described by a Simon-Glatzel equation of the form Tm = 1768(K )(P(GPa)/35.62+1)ˆ0.64. Finally, from the obtained results it was possible to determine a thermal equation of state for the cubic face-centred phase of Co.

Mots clés: Transition metals; Melting curve; Extreme conditions; Laser-heating; Diamond anvil cell

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Simone Anzellini, Silvia Boccato, Samuel Baty, Leonid Burakovsky, Daniele Antonangeli, et al.. Melting line and thermal equation of state of fcc-cobalt: A combined experimental and computational approach. Results in Physics, 2024, 56, pp.107218. ⟨10.1016/j.rinp.2023.107218⟩. ⟨hal-04311170⟩