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PbO–Sb2O3–B2O3 glasses mixed with different concentrations of Pr2O3 (ranging from 0 to 0.6 mol%) were crystallized. The samples were characterized by X‐ray diffraction (XRD) and transmission electron microscopy techniques. The XRD studies have revealed the presence of Pb5Sb2O8, Pb3(SbO4)2, PbB4O7, β‐PrSbO4, Pr3SbO7, and Pr3Sb5O12 crystalline phases. Optical absorption (in the visible and NIR regions) and fluorescence spectra of these samples have been recorded at room temperature. The Judd–Ofelt theory could successfully be applied to characterize the absorption and luminescence spectra of Pr3+ ions in these samples. From the luminescence spectra, various radiative properties like transition probability A, branching ratio βr, and the radiative lifetime τr for various emission levels originating from the 3P0 level of Pr3+ ion in the glasses glass ceramic samples have been evaluated. The radiative lifetime of the 3P0→3H6 transition is measured and the quantum efficiency has been estimated. The crystallization causes to improve the luminescence efficiency to a large extent. The changes observed in the radiative properties due to crystallization have been discussed in the light of varying co‐ordinations of antimony ions in the glass network.

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In this paper a steady three dimensional flow of a viscous-incompressible fluid through highly porous medium bounded by a vertical infinite porous plate under the influence of a transverse applied magnetic field, with periodic suction velocity is considered. Governing equations are solved by using perturbation technique and obtained the expressions for velocity and temperature. The above flow quantities are discussed through the graphs for different physical parameters. Also the expressions for shear stress and the rate of heat transfer coefficient are derived and discussed.