Five different types of spontaneous emission simultaneously observed in Tm2+ doped CsCaBr3

CsCaBr3 doped with 1% Tm2+ exhibits a rich emission spectrum at 10 K. Five emission bands are identified and characterised: a sharp and long-lived 4f-4f emission at 8796 cm(-1). Broad 5d-4f emission bands from the lowest energy (5d)(1)(4f)(12) configurations to the groundstate at 13640 cm(-1) ('spin-allowed') and 12240 cm(-1) ('spin-forbidden'). Two broad emission bands from a higher-energy f-d state, one centered at 19 115 cm(-1) to the F-2(7/2) groundstate and the other one at 10400 cm(-1) to the first excited F-2(5/2) state. The transitions are identified and the competition between radiative and nonradiative processes characterised from lifetime and temperature dependent measurements. (C) 2005 Elsevier B.V. All rights reserved.