Characterization and luminescence studies of Eu doped Barite nanophosphor

Barite (BaSO4) nanophosphors were successfully prepared by the co-precipitation method. The structural analysis of the sample was carried out by analytical techniques such as X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. XRD study reveals that the particles exhibit orthorhombic structure and are approximately 50 nm in size, while TEM study further confirms the particle size in the range 48-52 nm and depicts oval shape of the particles. The FTIR spectrum displays the bands centered at 1197 to1077 cm−1 and the shoulder at 982 cm−1 corresponding to the symmetrical vibration of SO42− ion. Moreover, S-O bending and stretching are the Raman signature of barite, which were proven by the Raman spectra, unveiling the various vibrational modes of the compound. Samples were irradiated by gamma rays and proton beams and their Thermoluminescent (TL) glow curves were plotted and studied. On applying two different types of irradiations in addition to large energy difference, the sample showed almost a similar TL glow curve structure, which is the remarkable feature of this phosphor. Analysis of the glow curve was also carried out by the glow curve deconvolution method. Photoluminescence (PL) study shows broad excitation spectra with the main peak at around 250 nm whereas the emission band excited by the wavelength 250 nm was observed at 374 nm which corresponds to the 4f65d→4f7 (8S7/2) transitions of Eu2+ ions. The sample was also examined for its PL response to different exposures of gamma irradiations where it showed an increase in the PL intensity up to a dose of 800 Gy for both excitation and emission spectra. The present sample shows good crystal quality along with high TL and PL sensitivity. Hence our results suggest possible potential applications of nanocrystalline BaSO4:Eu phosphor in dosimetric study of gamma and proton beams.