Since doping with Sm3+ increased both the anion and cation diffusion, the probable mechanism of Ca self-diffusion at near to 1000C was suggested to involve a vacancy mechanism. The migration energy was estimated to be about 1.5eV. At temperatures near to the melting point, vacancy pairs or Schottky trios could contribute to Ca self-diffusion. The formation energy of anion Frenkel pairs was between 2.2 and 3.1eV.

Fluorine Self-Diffusion in CaF2 and BaF2. H.J.Matzke: Journal of Materials Science, 1970, 5[10], 831-6

Table 159

Activation Energy for the Migration of F

in Doped CaF2 at 700 to 1100K