Synthesis and characterization of Dy3+ doped zincalead-phosphate glass

Dysprosium doped-zincalead-phosphate glasses having composition (60 - x) P2O5a20PbOa20ZnOaxDy2O3 where x = 0, 0.5, 1.0, and 3.0 mol% were prepared by melt quenching technique. Archimedes method was used to measure their densities that are used to calculate the molar volumes. The values of densities lie in the range 3.58a3.74 gm/cm3 whereas those of molar volume lie in the range of 40.80a41.10 cm-3. The UVaVISaNIR absorption spectroscopy in the wavelength range 300a1400 nm was carried out. Absorption spectra consist of eight absorption peaks corresponding to the transitions from the 6H15/2 ground state to various excited energy levels. Judd-Ofelt analysis of Dy3+ doped zincalead-phosphate is also accomplished. The energy band gap measured from the optical absorbance found to be in the range of 4.50a4.68 eV and 4.21a4.50 eV for direct and indirect transitions respectively. The IR spectra reveal the significant structural changes inside the glass induced by modifiers lead oxide and zinc oxide, explained in terms of the distortion of PO4 tetrahedra and network depolymerization process. Differential thermal analysis confirms the glass stability in the presence of Dy3+ ions. In addition, photoluminescence spectra shows three prominent emission bands centered at 475, 586 and 675 nm corresponds to the 4F9/2 a 6HJ (J = 11/2, 13/2, 15/2) transitions respectively and the intensity of all the bands are enhanced as the concentration of Dy3+ ions increased.