Pressure-Temperature Phase Diagram of Lithium, Predicted by Embedded Atom Model Potentials.

Autor: Dorrell J; Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, U.K., Pártay LB; Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, U.K.
Jazyk: angličtina
Zdroj: The journal of physical chemistry. B [J Phys Chem B] 2020 Jul 16; Vol. 124 (28), pp. 6015-6023. Date of Electronic Publication: 2020 Jun 30.
DOI: 10.1021/acs.jpcb.0c03882
Abstrakt: In order to study the performance of interatomic potentials and their reliability at higher pressures, the phase diagrams of two different embedded-atom-type potential models (EAMs) and a modified embedded-atom model (MEAM) of lithium are compared. The calculations were performed by using the nested sampling technique in the pressure range 0.01-20 GPa, in order to determine the liquid-vapor critical point, the melting curve, and the different stable solid phases of the compared models. The low-pressure stable structure below the melting line is found to be the body-centered-cubic (bcc) structure in all cases, but the higher pressure phases and the ground-state structures show a great variation, being face-centered cubic (fcc), hexagonal close-packed (hcp), a range of different close-packed stacking variants, and highly symmetric open structures are observed as well. A notable behavior of the EAM of Nichol and Ackland ( Phys. Rev. B: Condens. Matter Mater. Phys. 2016 , 93 , 184101) is observed, that the model displays a maximum temperature in the melting line, similarly to experimental results.
Databáze: MEDLINE