Low-temperature luminescence and energy transfer processes in Eu3+, Nd3+, and Cr-doped sol-gel PLZT ceramics

Luminescence and decay times of sol-gel PLZT(9/65/35) ceramics doped with Eu3+, Nd3+ and chromium ions are investigated to elucidate site occupancy and energy transfer processes at lower temperatures down to 10 K, in comparison with those prepared by mixed-oxide method. Luminescence and excitation energy transfer in sol-gel PLZT: Eu3+, Nd3+ are discussed with regard to trapping-limited energy transfer processes with critical distances of about 0.5 nm. The presence of three A sites in PLZT:Eu3+ under site-selective excitations and two B sites in PLZT : Cr3+, Cr5+ in NIR emission are confirmed at low temperatures. (C) 1999 Elsevier Science B.V. All rights reserved.