Magnetooptical studies of excited states of rare-earth ions in Y_3Al_5O_(12):Tb~(3+)

摘要

The energy spectrum of the ~7F_3 multiplet of a Tb~(3+) ion in one of the non-equivalent, positions (of D_2 symmetry) occupied by a rare-earth ion in the Y_3Al_5O_(12) crystallographic garnet structure is calculated. The energy spectrum of the ~7F_3state is characterized by the presence of quasi-doublet states formed by closely located Stark singlet states, that are effectively "mixed" in an external magnet field H. This inference is confirmed by the results of experimental studies of magnetopolarized luminescence on the radiative ~5D_4 -> ~7F_3 4f-4f transition in Y_3Al_3O_(12):Tb~(3+). The optical transitions are identified, and the components of the g-factor of the ~7F_3(GAMMA#_2,#GAMMA#_4) quasi-doublets in the Y_3Al_3O_(12) structure are determined.