Europium Doped Sr 2 YNbO 6 Double Perovskite Phosphor for Photoluminescence and Thermoluminescence Properties.

Luminescent double perovskite phosphor Sr 2 YNbO 6 doped with Eu 3+ crystallized to monoclinic phase were synthesized successfully via conventional high-temperature combustion synthesis. The formation of crystal structure, phase purity and surface morphology were studied via X-ray diffraction (XRD) and scanning electron microscopy (SEM). Characteristic vibrations between the atoms of the functional groups present in phosphor have been studied by Fourier transform infrared (FTIR) analysis. Luminescence properties of prepared phosphors were investigated in terms of photoluminescence (PL) and thermoluminescence (TL). PL excitation spectrum exhibits charge transfer band and characteristic 4f 6 transitions of Eu 3+ . Prominent PL emission is obtained for the phosphor doped with 4 mol% Eu 3+ under 396 nm excitation wavelength. For the higher doping concentration, PL emission quenching has been observed due to multipole-multipole interaction. Highly intense PL emission is arisen due to hypersensitive 5 D 0 - 7 F 2 electric dipole transition of Eu 3+ dominating in the emission spectra. The thermal stability of the phosphor was examined through the temperature dependent photoluminescence. Thermoluminescence properties of Sr 2 YNbO 6 double perovskites irradiated with 90 Sr beta source at different doses has been carried out. Double perovskite phosphors under study shows linear dose response with increasing beta dose ranging from 1 Gy to 10 Gy. Trapping parameters of the TL glow curves were determined by Chen's peak shape method and computerized glow curve deconvolution (CGCD). CGCD fitting of TL glow curves reveals, that it consists of three major peaks and followed the second order kinetics. Estimated activation energies determined by different methods were comparable and significant.