Dysprosium doped lead fluoroborate glasses: Structural, optical, and thermal investigations

Dy3+ doped lead fluoroborate (LFB) glasses (B2O3 + PbO + PbF2) have been prepared following conventional melt quenching technique by varying the concentration of Dy2O3 in the order 0.01, 0.1, 1, 2, and 3 mol%. X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), optical absorption, fluorescence emission, and decay curves have been recorded and analyzed. From the optical measurements and based on the Judd-Ofelt (JO) theory, the JO intensity parameters were evaluated and in turn used to evaluate the radiative transition probabilities (A), stimulated emission cross-section (sigma(E)(P)), radiative lifetimes (tau(rad)), and branching ratios (beta(R)) for the various F-4(9/2) -> H-6(J) (J = 11/2, 13/2, 15/2) transitions of Dy3+ ions in the LFB glasses and these values were compared with the other reported Dy3+: glasses. The decay curves of the F-4(9/2) level were measured and found to be deviate from the exponential nature with the increase in Dy3+ ion concentration. The luminescence quantum efficiency of the F-4(9/2) level was also determined and discussed. Differential scanning calorimetry (DSC) curves were used to evaluate the glass stability factor (S) and Hruby's parameter (H-R) through the glass transition (T-g), crystallization (T-c), and melting (T-m) temperatures and these results were discussed and reported. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim