Excitation energy transfer and low-temperature anomaly in luminescence of RE3+ codoped PLZT ceramics

Disordered PLZT(9/65/35) ceramics doped with (1) Tb3+/Sm3+ and (2) Eu3+/Yb3+ ions are investigated in luminescence and decay measurements at temperatures between 10 and 300 K. Resonant (1) and non-resonant (2) energy transfer mechanisms are found to give critical energy transfer distances of about 0.45 nm and they are confined by domain boundaries and porous size. PLZT:Eu3+ is found to elucidate luminescence anomalies at around 160 K which correspond to low temperature phase transitions. (C) 1998 Elsevier Science B.V. All rights reserved.