Thermally-stimulated luminescence and optical properties of Eu-doped MgAl2O4 transparent ceramics

Eu-doped MgAl2O4 transparent ceramics were synthesized by the spark plasma sintering technique as a new dosimetric material. The MgAl2O4 ceramics doped with Eu had the diffuse transmittance of 40–60% at longer wavelengths than 500 nm. The 0.01% Eu-doped MgAl2O4 showed the photoluminescence (PL) emission peak at 500 nm under the excitation at 300 nm, while the 0.1% Eu-doped MgAl2O4 clearly showed the PL emission peak at 600 nm under the excitation at 400 nm. These PL were due to 5d-4f transitions of Eu2+ ions and decayed within a few microseconds. The Eu-doped MgAl2O4 exhibited TSL glow peaks at 70, 250, 300, and 440 °C. The relative TSL intensity decreased to 95% within 1 day and was stable for 5 days. The TSL intensity of the 0.01 and 0.1% Eu-doped MgAl2O4 was detectable from 0.01 mGy and increased up to 1000 mGy with a linear relation.