Variation in the luminescence lifetimes of EuCl3 •nH2O (n=0,1,2,3,6)

Eu3+ ion emission spectra and luminescence lifetimes were investigated for EuCl3. nH(2)O (n=0,1,2,3,6). Each compound exhibited a characteristic set of emission bands and a specific luminescence lifetime. The number of water molecules and chloride ions coordinated to the Eu3+ ion in these materials was estimated from the observed lifetimes, spectroscopic implications, and expected lanthanide coordination numbers. Approximation of the observed luminescence decay constant for each material was possible through the use of arithmetic terms associated with both the complexed water molecules and the complexed chloride ions which make up the inner-coordination sphere of the Eu3+ ion.