Vacuum ultraviolet excitation and quantum splitting of Pr3+ in LaZrF7 and alpha-LaZr3F15

Excitation and emission characteristics of Pr-31 doped in LaZr3F15 and LaZr F7 at approximate to 293 and at approximate to 10 K are described. Synchrot ron radiation facilities were used. Both zirconium fluorides show quantum s plitting after excitation in the 4f5d configuration. The P-3(0) emission ha s an internal quantum efficiency close to unity while the D-1(2) emission i s completely quenched. It! LaZr3F15:1%Pr3+ broad emission and excitation ba nds are observed that are tentatively assigned to oxygen-to-metal charge tr ansfer. In LaZrF7 band-to-band or higher energy excitation result in the cr eation of self-trapped excitons (STEs), luminescent at 10 K. At 293 K energ y is transferred from STE to the P-3(0) state of Pr3+ and not to the ISO st ate. (C) 2001 Elsevier Science B.V. All rights reserved.