Zeeman and hyperfine infrared spectra of Pr3+ centers in alkaline earth fluoride crystals

Zeeman infrared studies of Pr3+ centers in alkaline earth fluorides identify principal centers of tetragonal C-4v symmetry for CaF2 and SrF2. Crystal-field analyses for these C-4v centers yield crystal-field parameters similar to those found for other trivalent rare-earth ions in CaF2 and SrF2. In BaF2:Pr3+, the principal center has a Pr3+ site of trigonal C-3v symmetry. Hyperfine structure on sharp infrared-absorption lines of the tetragonal centers are interpreted with magnetic-hyperfine constants calculated for the excited multiplets together with parameters introduced to account for the random-strain disorder.