Abstract

First-principles calculations based on density functional theory were used to study the high-pressure phases of both ZnF2 and CdF2. We found that the sequence of the pressure-induced phase transitions is: Rutile (P42/mnm) ↦ CaCl2 (Pnnm) ↦ PdF2 (Pa-3) and CaF2 (Fm3m) ↦ PbCl2 (Pnma) ↦ Ni2In (P63/mmc) for ZnF2 and CdF2 respectively. In ZnF2 the behavior of the ground-state total energy, of the Gibbs free energy and of the lattice constant vs. pressure shown that the phase transition at 4 GPa from the rutile-type phase to the CaCl2-type phase is a second-order phase transition. The mechanism of the structural change was also revealed by the transition from the PbCl2-type phase to the Ni2In-type phase in CdF2. Moreover, the high-pressure behavior of divalent metal fluorides was compared and discussed.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.