Interstitial Conduction in BaF2 Crystals

Abstract

The behavior of the $F^{-}$ interstitial in BaF₂ crystals has been examined using ionic‐conductivity measurements on BaF₂ crystals doped with various amounts of GdF₃. The interstitial mobility was found to be $${\text{μ\hspace{0.17em}=\hspace{0.17em}(4\hspace{0.17em}×\hspace{0.17em}10}}^3\mathrm{\hspace{0.17em}/\hspace{0.17em}T)}\exp \text{(−0.79\hspace{0.17em}±\hspace{0.17em}0.03\hspace{0.17em}/\hspace{0.17em}kT),}$$ and the association energy between the Gd³⁺ ion and the interstitial was 0.44 ± 0.04 eV. Very similar results were obtained for BaF₂ doped with monovalents halides. A detailed comparison between the present work, dielectric and anelastic loss measurements, and NMR studies has been made.