Abstract
In this paper the optical properties (emission and excitation spectra) of powder samples of the double oxides of RETa3O9 (RE = Tb, Eu) were analyzed. The results of lifetime measurements and time resolved experiments performed at 11 and 300 K are discussed. Within the range of the continuous solid solution Tb1-xEuxTa3O9, the optical characterization of our powder sample Tb0.9Eu0.1Ta3O9 is presented and combined with the previous results obtained by X-ray diffraction techniques to develop a better understanding on the effect of the RE ions on the crystalline structure of our samples.