Combustion Synthesis of SrAl2O4:Eu2+ Phosphor. Photoluminescence and Cathodoluminescence at Low Temperatures

Eu²⁺ doped strontium aluminate (SrAl₂O₄:Eu²⁺) nanosized phosphorescent powders were prepared by the urea-nitrate solution combustion method at 500°C for 5 min. The average particle size of the powders was about 80 nm. The photoluminescent properties were studied using ultraviolet excitation as well as high energy synchrotron radiation, and electron beam excitation. Broad photoluminescence bands were observed in SrAl₂O₄:Eu²⁺ peaking at λ_max = 450 and 520 nm which arise due to transitions from the 4f ⁶5d¹ to 4f ⁷ configuration of the Eu²⁺ ions situated in two sites with a different symmetry. One additional emission band was also observed at 360 nm. The nature of that band is under discussion.