Abstract
The thermostimulated luminescence (TSL) of powdered synthetic CaSO4 crystals is studied with various types of doping rare earth (RE3+) impurities: Dy3+, Tm3+, Ho3+, Er3+ or Gd3+. Fluorescence and optical diffuse reflectance data are presented. Valence changes of RE3+ are observed after X irradiation and/or thermal annealings. Defects in anionic SO42- groups (SOx types) are shown to be responsible for the UV lattice emission and the trapping centres, while the RE3+ ions are just radiative emission centres. The impact of the UV lattice emission on the energy transfer towards activators is confirmed. The TSL mechanism of CaSO4: RE3+ is finally discussed in the light of the observed optical properties and results from thermal annealing experiments.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have