Fluorescence features of Tm3+ ions in PbO–Sb2O3–B2O3 glass ceramics

The glasses of the composition (30−x)PbO–40Sb2O3–30B2O3: xTm2O3 with x ranging from 0.2–0.6 have been synthesized and subsequently crystallized. The samples were characterized by X-ray diffraction, SEM and DSC techniques. Optical absorption and fluorescence spectra (in the visible and NIR regions) of these samples have been recorded at room temperature. The Judd–Ofelt theory was successfully applied to characterize the absorption and fluorescence spectra of Tm3+ ions in glass and glass ceramic samples. From the luminescence spectra, various radiative properties like transition probability A, branching ratio βr and the radiative life time τr for various emission levels originating from 1G4 level have been evaluated for both glass and glass ceramic. The radiative life time of 1G4→3H6 (blue emission) transition has been measured and the quantum efficiency has been estimated for both glass and glass ceramic. It was established that the quantum efficiency was enhanced considerably due to the crystallization. The reasons for such enhancement have been discussed following differences in the environments of Tm3+ ions in the glass and glass ceramic network.