Beschreibung:
Lithium tetraborate (Li 2 B 4 O 7 ) is one of the tissue equivalent material that has been modified with numerous dopant/codopant to improve its Thermoluminescence (TL) and Optical stimulated Luminescence (OSL) properties. Li 2 B 4 O 7 doped with Al (Aluminium) is being investigated first time for OSL dosimetry in this paper. Polycrystalline nano-phosphor Li 2 B 4 O 7 :Al was synthesized using two step solid state reaction method with optimized concentration of Al equals to 2% (by wt.). Formation of the same and its morphology was confirmed using X-ray Diffractometry (XRD) and Transmission Electron Microscopy (TEM). The various dosimetric properties of the obtained phosphor along with related OSL kinetic parameters have been studied. The phosphor exhibits good linearity for gamma radiation in the range of 0.1-500 Gy with other properties such as low fading, satisfactory reusability & reproducibility and minimum detectable dose of 0.05 Gy . In this paper we have also explored the Temperature-Assisted OSL (TA-OSL) properties of Li 2 B 4 O 7 :Al in the range of 25 ֯C to 200 ֯C and the optimized temperature corresponding to the maximum OSL intensity was found to be 125 ֯C with activation energy equals to 0.108 + 0.02 eV. Li 2 B 4 O 7 :Al has also linear response with dose gamma (1-200 Gy) and beta (0.05-3 Gy) at 125 ֯C