Two-phase equation of state for lithium fluoride

We present an equation of state for the solid and liquid phases of lithium fluoride that covers a wide range of conditions from ambient pressure and temperature to the high pressures and temperatures exhibited in shock- and ramp-compression studies. The particular solid phase we have focused on in t...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of chemical physics 2019-02, Vol.150 (7), p.074506-074506
Main Authors: Myint, Philip C., Shi, Eric L., Hamel, Sebastien, Cynn, Hyunchae, Jenei, Zsolt, Lipp, Magnus J., Evans, William J., Akin, Minta C.
Format: Article
Language:English
Subjects:
Computer simulation
Equations of state
Fluorides
Hugoniot curves
INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Liquid phases
Lithium
Lithium fluoride
Molecular dynamics
Physics
Pressure
Solid phases
Velocimetry
Velocity measurement
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present an equation of state for the solid and liquid phases of lithium fluoride that covers a wide range of conditions from ambient pressure and temperature to the high pressures and temperatures exhibited in shock- and ramp-compression studies. The particular solid phase we have focused on in this work is the B1 phase. We have followed an approach where the pressure and heat-capacity functions of both phases are fit to experimental data and our own quantum molecular dynamics simulations and are then integrated in a thermodynamically consistent way to obtain the corresponding free-energy functions. This approach yields a two-phase equation of state that provides better overall agreement with experimental data than other equations of state for lithium fluoride, such as SESAME 7271v3, LEOS 2240, and the model presented by Smirnov. The last of these is a three-phase equation of state that predicts a B1–B2 transition along the shock Hugoniot at a pressure of about 140 GPa. This solid–solid transition has been a topic of speculation and debate in the literature for over 50 years, culminating in the work of Smirnov, who has developed the only potentially viable equation of state that allows for this transition. We explain why the proposed B1–B2 transition at 140 GPa is not consistent with recent velocimetry data.
ISSN:0021-9606
1089-7690
DOI:10.1063/1.5079758