SPECTROSCOPY AND TRANSFER PROCESSES IN LUXGD1-XALO3-CE SCINTILLATORS

Spectroscopic properties and energy transfer processes in Ce3+-doped R E3+AlO3 orthoaluminates (for RE3+ = Lu3+, Gd3+ or Y3+) Or for the mixe d LuxY1-x and LuxGd1-x are presented and summarised. Generally, spectr oscopic properties of these crystals are very similar but in their Ce3 + fluorescence and scintillation decay slow decay components appear. T emperature dependence of Ce3+ fluorescence decays in LuxGd1-xAlO3:Ce c rystals show Ce3+-->Gd3+ nonradiative energy transfer followed by the opposite transfer Gd3+-->Ce3+ (including migration through Gd3+ sublat tice) which is responsible for slow Ce3+ fluorescence decay component. Energy barrier between Ce3+ and Gd3+ interacting levels is similar to 70 meV.