Pressure effect on the ionic transport behavior and dielectric property of YF3

The ionic transport behavior and dielectric property of YF3 under high pressure were studied by AC impedance spectroscopy. All the transport parameters change discontinuously at 8.1 GPa and 16.7 GPa, corresponding to YF3 phase transition from Pnma to P (3) over bar c1. The ion diffusion coefficient and conductivity of P (3) over bar c1 phase increase with pressure increasing and all the conductivity values of P (3) over bar c1 phase under high pressure are larger than the value at atmospheric pressure. To Pnma phase, pressure decreases the lattice spacing and narrows the ion conduction channel; which leads to the ion diffusion coefficient and conductivity decreasing and the charge-discharge process more difficult. The lattice strain of P (3) over bar c1 phase increases under pressure, resulting in the ion diffusion coefficient and conductivity enhancing and the charge-discharge process easier. Pressure makes the ion hopping of P (3) over bar c1 phase easier and its permittivity increasing. (C) 2020 Elsevier B.V. All rights reserved.