Computer simulation studies were made of F--ion motion in the pure, or KF-doped, α-phase. It was found that aliovalent doping introduced vacancies that induced a significant degree of ionic motion, as reflected by nuclear magnetic resonance and conductivity data. The simulations involved polarizable ionic potentials that had already been shown to reproduce the properties of the superionic conducting β-phase, and the present results were consistent with experimental data. A site-hopping analysis was used to clarify the mechanism of vacancy-enhanced ionic motion, which differed markedly from the mechanism that was responsible for easy ion diffusion in the β-phase.

Ion Mobility in α-PbF2 - a Computer Simulation Study. M.J.Castiglione, M.Wilson, P.A.Madden, C.P.Grey: Journal of Physics - Condensed Matter, 2001, 13[1], 51-66