Effects of annealing on luminescence of CaWO4:Eu3+ nanoparticles and its thermoluminescence study

Abstract Eu 3+ doped CaWO 4 nano-sized phosphor powders with tunable optical properties were successfully prepared at comparatively low temperature (130 °C) in ethylene glycol (EG) medium and were further annealed to study heating effects in their luminescence properties. The particles exhibit the tetragonal scheelite structure. The luminescence study of the annealed nanoparticles leads to the confirmation that CaWO 4 :Eu 3+ shows a strong red emission at 614 nm originating from 5 D 0  →  7 F 2 transition. The optimum concentration of Eu 3+ for the highest luminescence is found to be 20 at.% and the luminescence intensities of the prepared nanoparticles increase with increasing annealing temperature from 500 to 900 °C. Thermoluminescence (TL) intensity of CaWO 4 :Eu 3+ with two prominent peaks at 393 and 514 K is found to be dependent on Eu 3+ concentration with highest TL intensity at 3 at.% of Eu 3+ .