Luminescence properties of Pr3+ in titanates and vanadates: Towards a criterion to predict 3P0 emission quenching (original) (raw)

Luminescence spectra of Pr 3+ in 15 titanate and vanadate lattices have been measured under UV excitation. They are characterized by a dominant red luminescence assigned to transitions from the 1 D 2 level to the ground state. The quenching of the otherwise prominent blue luminescence from 3 P 0 state is ascribed to a relaxation pathway involving a low-lying Pr 3+ -M n+ (M n+ = Ti 4+ or V 5+ ) intervalence charge transfer (IVCT) state. Complete quenching of the 3 P 0 emission takes place when the IVCT bands are located in the 26 500-28 000 cm À1 range and the shortest Pr 3+ -M n+ distances are in the 3.15-3.30 Å range.