213 research outputs found

    Host-sensitized phosphorescence of Mn4+, Eu3+, and Yb3+ in MgAl2Si2O8

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    Mn4+ doped and Eu3+, Yb3+ co-doped MgAl2 Si2O8-based phosphors were prepared by conventional solid state reaction at 1,300 C. They were characterized by thermogravimetry, differential thermal analysis, X-ray powder diffraction, photoluminescence, and scanning electron microscopy. The luminescence mechanism of the phosphors, which showed broad red emission bands in the range of 600–715 nm and had a different maximum intensity when activated by UV illumination, was discussed. Such a red emission can be attributed to the intrinsic 2E + 4A2 transitions of Mn4+

    Oxide ionic conductivity properties of binary δ-(Bi2O3)1 - x (Yb2O3) x system

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    In this study, after doping ytterbium oxide (Yb2O3) to a-bismuth trioxide (a-Bi2O3) in the range of 9% n 20% in a series of different mole ratios, heat treatment was performed by applying a cascade temperature rise in the range of 700–790 C for 48 hours and new phases were obtained in the (Bi2O3)1 x(Yb2O3)x system. After 24 hours of heat treatment at 700 C and 750 C and 48 hours of heat treatment at 790 C, mixtures containing 9–20 mol% Yb2O3 formed a face-centered cubic phase. With the help of X-ray diffraction (XRD), the crystal systems and lattice parameters of the solid solutions were obtained and their characterization was carried out. The surfaces of the solid solutions were detected by a scanning electron microscope (SEM). Thermal measurements were made by using a simultaneous DTA/TGA (differential thermal analysis/thermogravimetric analysis) system. The total conductivity (sT) in the d-Bi2O3 doped with Yb2O3 system was measured using the four-probe DC method

    1-Amino-5-(4-methyl­benzo­yl)-4-(4-methyl­phen­yl)pyrimidin-2(1H)-one

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    In the title compound, C19H17N3O2, the dihedral angles between the pyrimidine ring and the two benzene rings are 34.87 (12) (for the directly-bonded ring) and 69.57 (12)°. An intra­molecular N—H⋯O hydrogen bond occurs. The crystal packing features inter­molecular N–H⋯O hydrogen bonds
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