The impact of the synthesis conditions on SrAl 2 O 4 :Eu, Dy formation for a persistent afterglow

The design of phosphorescent materials, highly crystalline, with a submicron particle size is a challenge for industrial applications. Based on molten salt assisted process, the effects of salt/SrAl2O4 molar ratio on the phase evolution are studied. A significant influence of salt/SrAl2O4 molar ratio on synthesis and final properties has been observed. Moreover, the phase evolution has been explored as a function of treatment temperature. To remove the salt from the powder, the wash step is carried out with glycerin avoiding hydrolysis reaction due to the sensitivity of strontium aluminates to water. The salt/SrAl2O4 molar ratio of 3:1 and the thermal treatment at 1000 °C are preferred, avoiding extra wash step. Here, we have obtained highly crystalline SrAl2O4:Eu2 +, Dy3 + powder with a particle size ≤ 0.5 μm after a 2 h treatment at 1000 °C employing the molten salt approach. As a result, we believe that the general strategy described in this study opens the possibility of obtaining technologically relevant phosphors with enhanced properties, expanding their application range to radiation detection.