CRYSTAL FIELDS IN PR3+ DOPED RARE-EARTH GALLIUM GARNETS, RE3GA5O12PR3+

The optical absorption, site selective excitation and luminescence spectra of the trivalent praseodymium ion in three rare earth gallium garnet matrices, RE3Ga5O12 (REGG; RE=Y, Gd, and Pr) were detected at 4, 77 and 300 K. The 4f2 energy level schemes comprising 56 to 68 crystal field (CF) sublevels were simulated according to a phenomenological model taking into account both the free ion and CF effects. The model consisting of 17 parameters with 8 free ion and 9 CF parameters appropriate to the D2 point symmetry of the RE3+ site reproduced the experimental energy level schemes in a satisfactory manner with RMS deviations between 17 and 23 cm-1. The CF parameters vary only slightly as a function of the host matrix. The B(q)k parameter sets for PrGG and YGG:Pr3+ are consistent with those obtained for the other REGG and YGG:RE3+, respectively.