Influence of Li[sup +] and Na[sup +] Ions on the Dielectric Spectra of YbF[sub 3] Doped and LiF, NaF Codoped CaF[sub 2] Crystals

Various concentrations YbF3 ‐doped CaF2 and Li‐ (Na)‐ codoped crystals were grown using the conventional Bridgman method. The effect of Na+ and Li+ ions on the dielectric spectra was studied. The activation energy and the reciprocal frequency factor have been calculated in order to characterize the observed relaxations. An anomaly of e1 behavior (not reported before) has been observed which is assigned with a phase transition of the order‐disorder type.