14 research outputs found

    Synthesis of red phosphors based on borosilicate glass and NaMgSc0.5Lu0.5(MoO4)3:Eu3+ and Na0.5Mg0.5ScLu0.5(MoO4)3:Eu3+ NASICON phases of variable composition

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    Glass-ceramic materials based on NaMgSc0.5Lu0.5(MoO4)3:Eu3+ and Na0.5Mg0.5ScLu0.5(MoO4)3:Eu3+ NASICON phases of variable composition and borosilicate glass have been produced by solid-state reactions. The materials have been characterized by X-ray diffraction and differential thermal analysis, and their photoluminescence (excitation and emission) spectra have been measured. Their spectral characteristics have been analyzed with the aim of identifying materials potentially attractive as red phosphors

    Synthesis and luminescence of lead(II)-activated cadmium sulfide in poly(methyl methacrylate)

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    Optically transparent polymeric materials PMMA: Cd(Pb)S have been synthesized by polymerization of methyl methacrylate, which concurrently acts as a reaction medium for synthesis of metal sulfides, dispersion medium for the resulting colloidal solution forming during synthesis, and the base of compositions. Dependences of cadmium sulfide luminescence on the concentrations, concentration ratios of the initial compounds, reaction medium composition, and temperature have been established. The observed changes in the spectra are related to the introduction of lead(II) into compositions, complex formation on the surface of colloidal particles, and the effect of polar acetonitrile

    Synthesis and absorption and luminescence spectra of poly(methyl methacrylate):Cd(Mn,Pb)S composites

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    The reaction of cadmium, manganese, and lead trifluoroacetates with thioacetamide in methyl methacrylate yielded colloidal solutions of metal sulfides with different Cd(II): Mn(II): Pb(II) molar ratios. The colloidal particles were separated from solutions and examined by electron microscopy. Glassy polymer composites poly(methyl methacrylate):Cd(Mn)S and poly(methyl methacrylate):Cd(Mn,Pb)S were prepared by thermal polymerization of methyl methacrylate in the bulk. The transmittance of the composites at wavelengths larger than 480 nm is 92% at the sample thickness of 0.40 cm. The luminescence of the composites in the visible range is associated with cadmium sulfide. The corresponding absorption bands were recorded in the luminescence excitation spectra in the wavelength interval 300–450 nm. The effect of the matrix, Mn(II) and Pb(II) ions, and synthesis conditions on the absorption and luminescence properties of the composites was determined

    Synthesis and luminescence spectra of poly(methyl methacrylate)/CdS:Ln(III) composites

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    Cadmium sulfide was prepared by colloidal synthesis in methyl methacrylate (MMA). Europium and terbium salts were added to the colloidal solutions. Using MMA radical polymerization, we synthesized PMMA/CdS:Eu(III), PMMA/CdS:Tb(III), and PMMA/CdS:Eu(III):Tb(III) luminescent composites. Their luminescence is due to defects in the CdS crystals and the 5Dо → 7Fj and 5D4 → 7Fj electronic transitions of the Eu3+ and Tb3+ ions, respectively. It depends on the composition of the materials, complexation on the surface of the colloidal particles, heat treatment time during synthesis, excitation wavelength, and other factors

    Synthesis of red phosphors based on borosilicate glass and NaMgSc0.5Lu0.5(MoO4)3:Eu3+ and Na0.5Mg0.5ScLu0.5(MoO4)3:Eu3+ NASICON phases of variable composition

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    Glass-ceramic materials based on NaMgSc0.5Lu0.5(MoO4)3:Eu3+ and Na0.5Mg0.5ScLu0.5(MoO4)3:Eu3+ NASICON phases of variable composition and borosilicate glass have been produced by solid-state reactions. The materials have been characterized by X-ray diffraction and differential thermal analysis, and their photoluminescence (excitation and emission) spectra have been measured. Their spectral characteristics have been analyzed with the aim of identifying materials potentially attractive as red phosphors

    Red and green phosphors glow on the basis of oxide glass-ceramics doped with Eu3+ and Tb3+

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    Glass-ceramics phosphors were obtained by the introduction of the crystalline phase NaMg3Sc (MoO4)5:Eu3+,Tb3+ in the glass composition 8SiO2-20B2O3-5Lu2O3-31Bi2O3-36ZnO. The properties were characterized by X-ray diffraction (XRD), photoluminescence (PL) and photoluminescent excitation spectra (PLE). The XRD patterns were indicated NaMg3Sc (MoO4)5:Eu3+,Tb3+ crystallize well with the novel structure type and were assigned to the triclinic phase (space group PĪ, Z = 6). Glass-ceramic phosphors are well-known and promising as solid electrolytes, laser, luminescent and other inorganic materials. Luminescent properties of the phosphors are performed at room temperature. The excitation spectra of Eu-doped phosphor present strong absorption at 300 nm and the sharp peaks in the 350-500 nm range. Under the 394 nm excitation, intense red emission peak at 616 nm corresponding to 5D0→7F2 transition of Eu3+ is observed in the emission spectrum. The luminescence property indicates that the local symmetry of Eu3+ ion has no inversion center. The excitation spectra of Tb-doped phosphor by monitoring wavelength at 546 nm shows the intense broad band from 260 to 420 nm and the line at 234 nm, which is mainly attributed to charge-transfer band transition in MoO42- group, indicating the existence of energy transfer from MoO42- to Tb3+ in the Tb3+:glass-ceramic. The measured emission spectrum of Tb-doped phosphor has intense green emission at 546 nm corresponding to 5D4→7F5 transition of Tb3+, with λex=368 nm. The as-prepared phosphors may find potential applications in the field such as color displays, light-emitting diodes (LEDs) and optoelectronic devices

    Red and green phosphors glow on the basis of oxide glass-ceramics doped with Eu3+ and Tb3+

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    Glass-ceramics phosphors were obtained by the introduction of the crystalline phase NaMg3Sc (MoO4)5:Eu3+,Tb3+ in the glass composition 8SiO2-20B2O3-5Lu2O3-31Bi2O3-36ZnO. The properties were characterized by X-ray diffraction (XRD), photoluminescence (PL) and photoluminescent excitation spectra (PLE). The XRD patterns were indicated NaMg3Sc (MoO4)5:Eu3+,Tb3+ crystallize well with the novel structure type and were assigned to the triclinic phase (space group PĪ, Z = 6). Glass-ceramic phosphors are well-known and promising as solid electrolytes, laser, luminescent and other inorganic materials. Luminescent properties of the phosphors are performed at room temperature. The excitation spectra of Eu-doped phosphor present strong absorption at 300 nm and the sharp peaks in the 350-500 nm range. Under the 394 nm excitation, intense red emission peak at 616 nm corresponding to 5D0→7F2 transition of Eu3+ is observed in the emission spectrum. The luminescence property indicates that the local symmetry of Eu3+ ion has no inversion center. The excitation spectra of Tb-doped phosphor by monitoring wavelength at 546 nm shows the intense broad band from 260 to 420 nm and the line at 234 nm, which is mainly attributed to charge-transfer band transition in MoO42- group, indicating the existence of energy transfer from MoO42- to Tb3+ in the Tb3+:glass-ceramic. The measured emission spectrum of Tb-doped phosphor has intense green emission at 546 nm corresponding to 5D4→7F5 transition of Tb3+, with λex=368 nm. The as-prepared phosphors may find potential applications in the field such as color displays, light-emitting diodes (LEDs) and optoelectronic devices

    Synthesis and luminescence of lead(II)-activated cadmium sulfide in poly(methyl methacrylate)

    No full text
    Optically transparent polymeric materials PMMA: Cd(Pb)S have been synthesized by polymerization of methyl methacrylate, which concurrently acts as a reaction medium for synthesis of metal sulfides, dispersion medium for the resulting colloidal solution forming during synthesis, and the base of compositions. Dependences of cadmium sulfide luminescence on the concentrations, concentration ratios of the initial compounds, reaction medium composition, and temperature have been established. The observed changes in the spectra are related to the introduction of lead(II) into compositions, complex formation on the surface of colloidal particles, and the effect of polar acetonitrile

    Synthesis and luminescence spectra of poly(methyl methacrylate)/CdS:Ln(III) composites

    No full text
    Cadmium sulfide was prepared by colloidal synthesis in methyl methacrylate (MMA). Europium and terbium salts were added to the colloidal solutions. Using MMA radical polymerization, we synthesized PMMA/CdS:Eu(III), PMMA/CdS:Tb(III), and PMMA/CdS:Eu(III):Tb(III) luminescent composites. Their luminescence is due to defects in the CdS crystals and the 5Dо → 7Fj and 5D4 → 7Fj electronic transitions of the Eu3+ and Tb3+ ions, respectively. It depends on the composition of the materials, complexation on the surface of the colloidal particles, heat treatment time during synthesis, excitation wavelength, and other factors
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