Green emitting molybdate complexes in PbWO4 - results of an ODMR study

The nature of the green emission of PbWO4 is still under discussion, models ranging from WO3 groups over lead deficient phases to local distortions to wards a wolframite structure. In CaWO4 and PbMoO4 optically detected magnet ic resonance proved, using resolved Mo hyperfine structure, that tetrahedra l MoO4 complexes give rise to a green luminescence. Based on this, we have performed such experiments on a series of PWO samples from various sources and with different dopants. In all cases, we find resonances typical for Mo O4 groups, however, with strongly varying intensity depending on the Mo con tent of the crystals. These ODMR signals are connected with a luminescence band with a half width of 0.43 eV peaking at 508 nm. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.