Luminescence of Pr 3+ in minerals

Abstract

Time-resolved luminescence spectroscopy coupled with selective excitation allows one to identify and assign the emission transitions of Pr 3+ in natural apatite, scheelite and anhydrite. Under steady state conditions they are hidden by the stronger bands and lines of Eu 2+, (WO 4) 2−, (MoO 4) 2−, Sm 3+ and Dy 3+. Of special interest are the transitions from the 1S 0 level emitting in the UV part of the spectrum. These transitions make Pr 3+ doped oxyapatite and anhydrite potential materials for UV laser. The long-lived luminescence of Pr 3+ in the visible range in apatite in the presence of uranyl and in scheelite may be ascribed to the participation of the 1S 0 level which serves as a trap of the excitation.