Dielectric spectra of Li+(Na+) codoped CaF2:YbF3crystals

Calcium fluoride crystals doped with YbF3 and codoped with NaF, LiF were grown using the vertical Bridgman method. The effect of Na+ and Li+ ions on the optical and dielectric spectra was studied. The relaxation parameters (the activation energy for dipole reorientation and relaxation time constant) and the number of the dipoles, ND, that contribute to the dielectric relaxation have been determined from the dielectric spectra. The correlation between ND and the optical spectra is also discussed. A comparison of our results with those obtained by other authors is also given. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)