Solubility of CaO in CaF2 crystals

By means of conductivity investigations the solubility of CaO in CaF₂ crystals was estimated to be C_L(CaO) ≈︁ 3.7 exp (-0.68 eV/kT) = 3.7 exp (-7900 K/T) and the diffusion constant of O⁻ ions in CaF₂ D(O⁻) ≈︁ 3 exp (-2.2 eV/kT) cm²/s = 3 exp (-25 500 K/T) cm²/s.