Structure, luminescence and scintillation characteristics of Yb, Na, Ba-codoped yttrium-aluminum garnet

High-quality Yb-doped Y3Al5O12 [yttrium–aluminum garnet YAG] crystals and Na, Ba co-doped Yb:YAG crystals with diameter of 65mm were grown from melt by the Czochralski method. The chemical of the two crystals are (Yb_0.1Y_0.899)₃Al₅O₁₀ and (Na_0.0005Ba_0.0005Yb_0.1Y_0.899)₃Al₅O₁₀. The structure, photoluminescence properties and scintillation yield were studied. The prepared samples are identified as pure garnet structure by the XRD results, indicating that the co-doping of a small amount of Na, Ba ions has no influence on the structure of the host. Thermoluminescence glow curves with the temperature showed that there were 100℃ and 260℃ thermoluminescence peaks in the two kinds of crystals, but the peak intensity of co-doping sample decreased, which suggested the number of defects decreased significantly. Light output in co-doped crystals reaches 110% comparative to Yb:YAG crystals and the sensitivity increased by 40%. This suggests that trace ions co-doping may be a possible way to reduce the crystal defect and increase the optical output.