Effect of co-doping on luminescence of LiCaAlF₆:Eu phosphor

Abstracts: LiCaAlF₆ is a versatile host material. Applications of this host as scintillation detector and solid state laser have been reported quite frequently. Thermoluminescence studies on LiCaAlF₆:Eu have also been reported. They are, however, not consistent. The glow curve structure depends on the synthesis route. At least two glow peaks are observed, around 180 °C and 240 °C. Effects of co-doping on the glow curve are reported. Co-doping with Y (0.5 mol%) suppresses the 240 °C peak and increases the intensity of 180 °C peak nearly 3 fold and shifts it to slightly higher temperature of 190 °C. Co-doping with La (0.8 mol%), on the other hand, removes 180 °C peak and intense peak at 240 °C can be observed. Thus co-doping produces a relatively simple glow curve with only one dominant peak. LiCaAlF₆:Eu phosphor also shows intense optically stimulated luminescence (OSL). The OSL sensitivity of LiCaAlF₆:Eu codoped with Y is about 7 times that of commercially available Al₂O₃:C. Other OSL properties useful for dosimetry applications are also reported in this paper. - Highlights: • Precipitation synthesis of LiCaAlF₆:Eu, Yttrium co-doping simplifies glow curve. • TL sensitivity is 3 times that of CaSO₄:Dy. • OSL sensitivity is 7 times that of Al₂O₃:C (Landauer). • Linear OSL response in the range 3 mGy to 1 kGy. • Negligible fading over 40 days