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RESEARCH PRODUCT
High-Pressure, High-Temperature Phase Diagram of Calcium Fluoride from Classical Atomistic Simulations
Claudio CazorlaDaniel Errandoneasubject
Range (particle radiation)Materials scienceThermodynamicschemistry.chemical_elementInteratomic potentialSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsCrystalsymbols.namesakeMolecular dynamicsGeneral EnergychemistrysymbolsFluorinePhysical and Theoretical Chemistryvan der Waals forceParametrizationPhase diagramdescription
We study the phase diagram of calcium fluoride (CaF2) under pressure using classical molecular dynamics simulations performed with a reliable pairwise interatomic potential of the Born−Mayer−Huggins form. Our results obtained under conditions 0 ≤ P ≲ 20 GPa and 0 ≤ T ≲ 4000 K reveal a rich variety of multiphase boundaries involving different crystal, superionic, and liquid phases, for all of which we provide an accurate parametrization. Interestingly, we predict the existence of three special triple points (i.e., solid−solid−superionic, solid−superionic−superionic, and superionic−superionic−liquid coexisting states) within a narrow and experimentally accessible thermodynamic range of 6 ≤ P ≤ 8 GPa and 1500 ≤ T ≤ 2750 K. In addition, we examine the role of short-ranged repulsive (SR) and long-ranged van der Waals attractive (LA) interactions in the prediction of melting lines with the finding that SR Ca−F and LA F−F contributions are most decisive.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2013-05-20 | The Journal of Physical Chemistry C |