It was found that the migration enthalpy of fluoride interstitials in the dilute solid solutions was equal to 0.946eV. The dissociation enthalpy of the neutral associates, [YbSrFi]x, was equal to 0.56eV. This value agreed with theoretical estimates of the binding energy. From an analysis of conductivity data for SrF2, it was deduced that the energy for intrinsic defect formation in the latter was equal to 2.70eV.

J.Schoonman, H.W.Den Hartog: Solid State Ionics, 1982, 7[1], 9-12