96 research outputs found
Anneal-induced transformation of phase structure, morphology and luminescence of GdPO4:Sm3+ nanomaterials synthesized by a hydrothermal method
No full textGdPO4 center dot H2O:xSm(3+) nanomaterials were synthesized via a facile hydrothermal method and the effects of Sm3+ concentrations and annealing temperature on the crystal structures, morphologies, and luminescent properties were studied. Doping of Sm3+ exhibited no obvious influence on the crystal structure for the non-annealed samples, which possessed a hexagonal structure and a nanorod shape. Under 401 nm excitation, GdPO4 center dot H2O:xSm(3+) displays a typical emission band with several peaks at 560, 596, and 640 nm. For the optimal sample of GdPO4 center dot H2O:1.75%Sm3+, as the annealing temperature was increased from 300 to 800 degrees C, the compound transformed from GdPO4 center dot H2O with a hexagonal symmetry to anhydrous GdPO4 with a monoclinic symmetry, and the morphologies varied from nanorods to ellipse-like shapes. The length of the nanorods was about 200 nm, whereas the ellipse-like shape exhibited a length of 100 nm and a diameter of 50 nm. The luminescent intensity was enhanced with the increased annealing temperature because the compound transformed from GdPO4 center dot H2O to anhydrous GdPO4 and the non-radiative transition was reduced due to variation in the morphology. Moreover, GdPO4 center dot H2O:1.75%Sm3+ exhibits paramagnetic performance. In addition, the potential applications in bioimaging and MRI were investigated
Structure and piezoelectric properties of K0.5Na0.5NbO3–Bi0.5Li0.5TiO3 lead-free ceramics
No full textPhase transition, dielectric and piezoelectric properties of K0.5Na0.5NbO3–CaTi0.9Zr0.1O3 lead-free ceramics
No full textMicrostructure, piezoelectric and ferroelectric properties of Mn-added Na0.5Bi4.5Ti4O15 ceramics
No full textStructure, ferroelectric, piezoelectric and ferromagnetic properties of BiFeO3–Ba0.85Ca0.15Ti0.90Zr0.10O3 lead-free multiferroic ceramics
No full textA sustainable hierarchical carbon derived from cultivated fibroid fungus for high performance lithium–sulfur batteries
No full textControlling the fabrication of microorganism at an earlier stage, the final properties of this biomass carbon can be changed.</p
Structure and luminescent properties of Ca3Bi(PO4)(3):Sm3+ orange phosphor
No full textA series of orange-emitting Ca3Bi1-x (PO4)(3):xSm(3+) phosphors were synthesized by a solid state reaction, the crystal structure and luminescent properties of the materials were studied. The doping of Sm3+ has no obvious influence on the crystal structure of the Ca3Bi(PO4)(3) powders and all the samples possess a cubic symmetry. Under the 401 nm excitation, the sample exhibits three typical emission bands located at 561, 598, and 644 nm corresponding to (4)G(5/2) -> H-6(5/2), H-6(7/2), and H-6(9/2) transitions, respectively. For x = 0.03, the sample exhibits an optimum luminescence. The type of energy transfer between Sm3+ is considered as dipole-dipole interaction according to Dexter's theory. The CIE chromaticity coordinates indicate that the emission of Ca3Bi0.97(PO4)(3):0.03Sm(3+) locates in orange region. The results indicate that the phosphor may be used as an orange phosphor for NUV-based white LEDs
Morphology-controlled synthesis, growth mechanism and fluorescence of YF3:Eu3+, Bi3+
No full textIn recent years, morphology-controlled synthesis and corresponding property tuning in inorganic materials have attracted considerable attention. In this work, lanthanide luminescent materials of YF3:0.125Eu(3+), 0.5%Bi3+ with a variety of well-defined morphologies including spherical, truncated octahedron, octahedron and pseudo-sphere particle have been controllably synthesized via a facile hydrothermal method. Phase structure and morphology of the materials are tuned, and thus fluorescent properties are tailored by changing the synthetic parameters of reaction temperature and dwelling time. With increasing reaction temperature, the materials are transformed from KY3F10 to YF3, and the morphology varies from spherical to octahedron and finally truncated octahedra. When dwelling time increases, the samples also extend from KY3F10 to YF3 and the morphology changes from spherical to octahedron, then truncated octahedra and finally pseudo-sphere particle. The possible growth mechanism for diverse morphologies has been proposed. The fluorescence intensity of the materials is closely related to their morphologic characteristics. The YF3:0.125Eu(3+), 0.5%Bi3+ with truncated octahedra synthesized at 200 degrees C for 18 h presents the strongest emission intensity because of its less defects sites and large grain size. In addition, it has been demonstrated that the present luminescent materials can be potentially used as the luminescent ink. (C) 2017 Elsevier Ltd. All rights reserved
Red/Blue-Shift Dual-Directional Regulation in Blue-Emitting Ca0.8Ba1.2SiO4:Eu2+ Phosphor on Incorporation of Eu2+/Mg2+ Ions
No full textBlue-emitting phosphors with composition (Ca0.8Ba1.2)(1-x) Mg (x) SiO4:yEu(2+) (x = 0 to 0.11, y = 0.01 to 0.08) have been synthesized via a high-temperature solid-state reaction route and the effects of Mg2+ and Eu2+ codoping on their morphology, crystal structure, and luminescence properties were investigated. For (Ca0.8Ba1.2)(1-x) Mg (x) SiO4:0.04Eu(2+), the color changed from light-blue to deep-blue region with increasing Mg2+ content from x = 0 to x = 0.11. For (Ca0.8Ba1.2)(0.93)Mg0.07SiO4:yEu(2+), the emission band showed the opposite shift with increasing y from 1% to 8%. Interestingly, increasing Mg2+ addition led to significant reduction in the full-width at half-maximum (FWHM) from 100 nm to 70 nm. Compared with Mg-free samples, the emission intensity of the Mg-containing material with x = 0.07 was enhanced by similar to 100%. The optimum doping levels of Mg2+ and Eu2+ were 0.07 and 0.02 for (Ca-0.8 Ba-1.2)(1-x) Mg (x) SiO4:0.04Eu(2+) and (Ca0.8Ba1.2)(0.93)Mg0.07SiO4:yEu(2+), respectively. These results indicate that such materials could be good candidate blue-emitting phosphors for use in solid-state lighting and displays
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