Energy transfer in aluminum oxide codoped with terbium and europium

The light emission of lanthanide impurity ions in granular host materials depends on how the impurities are incorporated. Impurities randomly substituted throughout a host have little interaction in dilute materials, but when impurities cluster together, interactions between the impurities gain importance. Thus, the study of impurity ions can reveal information about the crystal structure of the host and how the impurities are incorporated. In this research, we synthesized alumina doped with different combinations of Eu³⁺ and Tb³⁺ using a sol-gel method. Varying the sintering temperature, we transform the alumina host through a series of known structures. The absorption and excitation spectra in the visible range are measured. We demonstrate (Donor to Acceptor) energy transfer from the terbium to europium impurities. And the energy transfer is more likely with higher Tb (donor) concentration and varies insignificantly with change in structural forms.