Laser-induced time-resolved luminescence of rare-earth elements in scheelite

Natural and synthetic scheelite are investigated by time-resolved laser-induced luminescence to detect and ascribe various luminescence lines to a variety of REE. The selectivity of detection is possible by using different time delays after excitation, different gate widths and different excitation wavenumbers and allowed to detect REE in samples where they are hidden by intrinsic luminescence and not visible in the steady-state spectra as well as by cathodoluminescence. Luminescence of Pr³⁺, Er³⁺ and Tm³⁺ are detected even with low concentrations and in the presence of Tb³⁺, Dy³⁺ and Sm³⁺. Luminescence of Ho³⁺ and Yb³⁺ is firstly detected in natural scheelites and luminescence of Eu²⁺ and Ce³⁺ is preliminary suggested.