Dielectric spectra of divalent rare-earth metal ions in LaF3 crystals

Abstract

The dielectric spectra of LaF3 crystals activated by rare-earth ions Eu2+, Sm2+, and Yb2+, gradually cooled from 300 to 240 K, were investigated. Obtained experimental data were compared with experimental data obtained previously by other authors. The reorientation activation energies for RE2+ dipoles in LaF3 are 0.49, 0.55, 0.56, and 0.58 eV for Ba2+, Sm2+, Eu2+, and Yb2+, respectively. A reorientation of fluorine vacancy is observed, across the F1 positions.