EXCITATION AND DESEXCITATION PROCESSES OF EU3+ LUMINESCENCE IN EU2BAZNO5

Luminescence and Raman crystal field transitions of Eu3+ ions in Eu2Ba ZnO5 are investigated in off-resonance conditions for several excitati on energies. Luminescence peaks are identified and classified into two groups (transitions from D-5(0) and those from D-5(1) or D-5(2)) as a function of their relative intensity versus temperature. Crystal fiel d parameters are found to be very similar for both europium sites. Ram an crystal field transitions are studied as a function of temperature. The increase of their intensity when temperature is lowered is explai ned by the change of the ground state population. The behaviour of the luminescence at several excitation energies has been explained by mea ns of second-order processes. The lattice phonons and thermal populati on of the lowest excited multiplets have a determining role in the exc itation processes of Eu luminescence. (C) 1998 Elsevier Science S.A.