Bioinfo Publications 82 WET CHEMICAL SYNTHESIS OF Tb3+ AND Eu3+ DOPED Na2Sr2Mg(BO3)2F2 PHOSPHOR FOR TL

Abstract- This paper reports the luminescent properties of Tb3+ and Eu3+ doped triple mixed borate (Na2Sr2Mg(BO3)2F2) synthesized by simple wet chemical route. Phosphor has been studied for photoluminescence and thermoluminescence characterizations. PL emission spectra of Na2Sr2Mg(BO3)2F2:Tb3+ shows four peaks showing optimum intensity at 545nm monitored at excitation wavelength 370 nm. The emission spectra exhibit four main bands with the maxima at about 490, 545 (the highest one), 587, and 626 nm, which are due to the tran-sitions from the excited state 5D4 to the ground states 7FJ (J=6, 5, 4, 3) of Tb3+ in the host lattice. PL emission spectra of Eu doped Na2Sr2Mg (BO3)2F2 phosphor shows two well resolved peaks around 593nm and 618nm which are assigned to 5D0→7F1 and 5D0→7F2 transition of Eu3+ ion and a peak around 425nm due to 4f65d1→4f7 transition of Eu2+ in the blue region of visible spectrum. Thermoluminescence glow curves of Na2Sr2Mg(BO3)2F2 phosphor doped with Eu3+ and Tb3+ ions exposed to 0.5 kGy irradiation dose of 60Co are illustrated. TL glow curves consist of only one peak which is fairly symmetrical. Glow peak is observed at 221ºC for Eu3+ doped host and TL intensity is about 2 times less than standard CaSO4:Dy. These properties about the phosphor may prove this a good candidate for TL dosimetry