Abstract
Luminescence spectra of lanthanides in the vacuum ultraviolet spectral region have revealed interesting features for transitions. For and in weak bands are present in the excitation spectra at lower energy than the usually observed strong bands. The weakness of the bands is explained by the spin-forbidden character of transitions from the ground state to these states. For and upon excitation in the higher energetic states two kinds of emission are observed: fast spin-allowed emission with a decay time in the order of ns, and slow spin-forbidden emission with a decay time in the order of μs. These two types of emission are also found for and in other fluoride hosts.
- Received 17 May 1999
DOI:https://doi.org/10.1103/PhysRevB.60.10820
©1999 American Physical Society