Luminescence of Doped and Undoped Al2 ( WO 4 ) 3, Sc2 ( WO 4 ) 3, and Lu2 ( WO 4 ) 3

The luminescence of doped (Eu3+, Cr3+) and undoped ,, and has been investigated. The tungstate luminescence is not very efficient for reasons closely related to the packing of the crystal structure, and are very hygroscopic. The Eu3+ emission can be used as a tracer for the moisture amount of these tungstates. At 4.2°K the Cr3+ emission consists of 2E line emission ( and lines). In the vibronic structure coupling with tungstate vibrational modes have been observed. At higher temperatures the emission takes over.