Thermoluminescence and kinetic study of low z LiAlO₂:Dy/Eu phosphors

ABSTRACT

In the present article, polycrystalline low Z (Z_eff = 8.19) LiAlO₂:Dy/Eu phosphor prepared by simple wet chemical method. Thermoluminescence and some of the dosimetric characteristics of Dy/Eu activated LiAlO₂ were reported. Samples in powder form were exposed to γ-ray irradiation with 137 Cs source for both LiAlO₂:Dy and LiAlO₂:Eu phosphors were studied for the first time. In case of LiAlO₂:Dy phosphor shows one peak at 287°C and small hump at 335°C. However; LiAlO₂:Eu phosphor shows glow peak at 272°C with a shoulder peak around 329°C. The TL sensitivity in both the cases were compared with CaSO₄:Dy phosphor.LiAlO₂:Dy sample have shown 1.23 times less sensitive than CaSO₄:Dy and for LiAlO₂:Eu is 5.6 times less sensitive than CaSO₄:Dy.The TL response in the 0.001-0.043Gy dose range increased linearly with increase in radiation dose for both the samples. Fading study has been also done for both the samples. In addition to this trap parameters of LiAlO₂:Dy/Eu were calculated by using computerized glow curve deconvolution and Chen's peak shape method.

KEYWORDS:

• Thermoluminescence (TL)
• γ-ray irradiation
• dosimetry
• phosphor
• TL glow curve

Acknowledgments

Authors MRK and PWY are thankful to the UGC, New Delhi, for providing financial assistance to carry out the research work. The authors are also grateful to Director, Inter-University Accelerator Centre (IUAC), New Delhi, for providing beam line and other instrumentation.