Asian Research Thesis Index

Abstract

Li2O–Gd2O3–MO–B2O3 glasses, where MO=Bi2O3, BaO doped with different rare earth ions (Sm3+, Dy3+, Eu3+ and Ce3+) have been synthesized by conventional melt quenching technique for the applications of solid state lightning devices (color LEDs), lasers and scintillation detectors. The developed glass samples have been investigated and characterized through their physical (density, molar volume, refractive index and optical energy gap, etc.), structural (X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR)) and optical (absorption, excitation, emission and decay) properties. The various spectroscopic parameters such as, Judd-Oflet (JO) intensity parameters (Ωλ=2,4,6), radiative lifetime (τR), transition probability (AR), branching ratio (βR), quantum efficiency (η), non-radiative relaxation rates (WNR), effective bandwidths (∆λeff), stimulated emission cross-section σ(λp) and CIE color coordinates for the present thesis have been calculated and analyzed by using various theoretical models and different mathematical relations, which shows the same trend for all developed glass samples. The structural properties of the developed glasses have been investigated through XRD and FTIR spectra. The optical band and JO intensity parameters have been evaluated from optical absorption spectra. The optical and luminescence properties of the prepared glasses have been study with the help of absorption, transmittance, and photoluminescence and X-ray luminescence spectrum. Lifetime of all the developed glasses have been found to decrease with increase in concentration of rare earth ions. The energy transfer mechanism has been explained by using InokutiHirayama (IH) model, which shows better fitting for S=6, which is dipole-dipole interaction is dominant in the present glass samples. From the color coordinates values of LGBiBSm and LGBaBSm glasses emits orange light while LGBiBDy, LGBaBDy and LGBiBEu glasses emits white and red light, respectively. From the obtained results, LGMOBSm, LGMODy, and LGBiBEu glasses could be the potential hosts for the light emitting diodes and laser applications. While LGBaBCeF glasses might be used for the neutron detection.

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