205 resultados para CEF3-TB3
Resumo:
Ternary complexes of europium and terbium with paraaminobenzoic acid and 1,10-phenanthroline (Eu(p-ABA)(3). phen . 2H(2)O and Tb(p-ABA)(3). phen . 2H(2)O, where p-HABA = paraaminobenzoic acid and phen = 1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The luminescence behavior of the complexes in silica gels was studied in comparison with the. corresponding solid-state complexes by means of emission, excitation spectra, and Lifetimes. Within the range of effective dopant concentrations, the luminescence intensities of rare-earth complexes in silica gel increase with the increasing of their dopant concentration. The lifetimes of rare-earth ions (Eu3+ and-Tb3+) in silica gel doped with europium and terbium complexes become longer than those in pure complexes. Very small amounts of rare-earth complexes doped in silica gel matrix can exhibit excellent luminescence properties, (C) 1998 Elsevier Science Ltd.
Resumo:
Europium and terbium complexes with 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the complexes in silica gels was studied compared with the corresponding solid state complexes by means of emission, excitation spectra and lifetimes. (C) 1998 Published by Elsevier Science S.A. All rights reserved.
Resumo:
Binary and ternary complexes of europium and terbium with conjugated carboxylic acid (nicotinic acid and 3,4-furandicarboxylic acid) and 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the complexes in silica gels was studied compared with the corresponding solid state complexes by means of emission, excitation spectra and lifetimes. The result indicated that the rare earth ions (EU3+ and Tb3+) showed fewer emission lines and slightly lower emission intensities in the silica gel than those in pure rare earth complexes. The lifetimes of rare earth ions (EU3+ and Tb3+) in silica gel doped with rare earth complexes became longer than those in pure rare earth complexes. (C) 1998 Elsevier Science S.A.
Resumo:
The BaB4O7:Eu, Tb phosphors are first synthesized in air atmosphere. We investigate their luminescent properties, and find that europium(II) and europium(III) can coexist in the BaB4O7:Eu phosphor. We observed that the relative intensity of europium(II) is increased when terbium(III) is incorporated. The electron spin resonance (ESR) spectra are carried out. The intensity of ESR peaks corresponding to europium(II) is also increased when terbium(III) is increased, so the valency state of europium is influenced by terbium(III). We explain these phenomena by an electron transfer mechanism. (C) 1996 Academic Press, Inc.
Resumo:
The luminescence properties of Ce3+, Tb3+, Sm3+ and energy transfer from Ce3+ to Tb3+ were studied in two modifications of Y2SiO5 (low temperature X(1) type and high temperature X(2) type). The Ce3+ cation shows lower emission energy and larger Stokes shift in X(1)-Y2SiO5 than in X(2)-Y2SiO5, and the emission intensities of Ce3+, Tb3+, Sm3+ in the former are weaker than those in the latter. There exists an energy transfer from Ce3+ to Tb3+ in both types of Y2SiO5, and the transfer efficiency in X(2) type is higher than that in X(1) type. All of these results are discussed in relation to the crystal structure of Y2SiO5.
Resumo:
Ca4Y6(SiO4)(6)O:A (A = Pb2+, Eu3+, Tb3+, Dy3+) phosphors have been prepared by two methods: the sol-gel method and the conventional dry method. The crystallization processes and the luminescence characteristics of the phosphors were studied, The sol-gel method features low-temperature formation of the phosphor, leading to successful preparation of Pb2+-activated phosphors which could not be prepared by the dry method at high temperature. The (4f)(8-)(4f)(7)(5d)(1) absorption band of Tb3+ and the charge-transfer (CT) band of Eu3+ have higher energies and narrower half-widths in the sol-gel-derived phosphors than in the phosphors prepared by the dry method, respectively. The Tb3+ and Dy3+ ions show stronger emission in the former than in the latter. Both the yellow-to-blue intensity ratio (Y:B) of Dy3+ and the red-to-orange intensity ratio (R:O) of Eu3+ in the sol-gel-derived phosphors are smaller than those for the phosphors derived by the dry method.
Resumo:
In this paper, we report on the multicolor luminescence in oxygen-deficient Tb3+-doped calcium aluminogermanate glasses. A simple method was proposed to control oxygen-deficient defects in glasses by adding metal Al instead of the corresponding oxide (Al2O3), resulting in efficient blue and red emissions from Tb3+-undoped glasses with 300 and 380 nm excitation wavelengths, respectively. Moreover, in Tb3+-doped oxygen-deficient glasses, bright three-color (sky-blue, green or yellow, and red) luminescence was observed with 300, 380, and 395 nm excitation wavelengths, respectively. These glasses are useful for the fabrication of white light-emitting diode (LED) lighting.
Resumo:
nyYAlO3CeYAPCe15ACeF3NaIYAPCe125MeVCeF3NaI402mmYAPCeCeF2NaI1644
Resumo:
IIYZ(D1-Y161)IIII(OEC) PSII LaCl3TbCl3Co2Ni2PSII 1. PSII , -PSII; 2. PSII , CaCl2Ca2+Mn3(III)>Mn(III)Mn(III)> Mn(III)Mn(IV) 3. LaCl3 TbCl3 IILa3+Tb3+IICa2+Ca2+ 10 mmol/L Ca2+50%50%PSII10 4Ni2Co2IINi2Co2II17 kDa23 kDaIICaCl25 mmol/L17 kDa10 mmol/L17 kDa 23 kDaMnCa
Resumo:
Terbium ions were successfully incorporated in nano-sized zinc oxide particles with a doping concentration up to 3% by using a wet chemical route. Four narrow emission peaks of Tb3+ ions and a broad emission band of the surface states on ZnO nano-hosts were observed for all Tb-doped nanoparticles. Relaxation of carriers from excited states of ZnO hosts to rare earth (RE) dopants is disclosed by the fact that the emission intensity of Tb3+ centers increases with increased Tb content at the expense of the emission from surface defect states in ZnO matrix. (C) 2001 Elsevier Science B.V. All rights reserved.
Resumo:
Terbium-doped zinc oxide nanoparticles have been prepared by hydrolyzing zinc acetate and terbium acetate. Nanoparticle-matrix-facilitated photoluminescence which is related to Tb3+ ions has been observed for ZnO:Tb nanoparticles. The dependence of emission intensity on doping concentration of Tb3+ ions has been investigated. An energy transfer from excited states of ZnO hosts to dopants is disclosed by the fact that the emission intensity of Tb3+ centers increases with increasing Tb content at the expense of emission from defect states in ZnO matrix.
Resumo:
Tb3+-doped zinc oxide nanocrystals with a hexagonal wurzite structure were successfully prepared by reaction between Zn-O-Tb precursors and LiOH in ethanol. Good incorporation of Tb3+ in ZnO nanocrystals is proved by XRD, FTIR, PL and PLE measurements. The presence of acetate complexes to zinc atoms on particle surfaces is disclosed by FTIR results. Emission from both Tb3+ ions and surface states in ZnO matrix, as well as their correlation were observed. The luminescence mechanism is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.
Resumo:
Cyanex 923Ce(IV)Ce(III)Ce(III)CeIVCe(III)Cyanex 9230.5g/L98% 254nmTiO2CeF3 Cyanex 923P204Ce(IV)FCe(IV)-FCe(IV)Ce(IV)-FCeF Cyanex 923P204
Resumo:
// (Na3C6H5O7•2H2O)(NaF, NH4FNaBF4)pHLnF3 (Ln = La-Lu)NaREF4 (RE = Y, Yb, Lu)(Yb)(Lu)Eu3+, Tb3+Yb3+/Er3+, Yb3+/Ym3+(LEDs)/ CaWO4, CaWO4:Eu3+CaWO4:Tb3+
Resumo:
Field Emission Displays, FEDFEDFED (FED)(FED)-(FED) [(LaGaO3: Re3+ (Re = Eu, Tb, Dy, Tm, Sm)][(CaIn2O4: Re3+ (Re = Eu, Pr, Tb, Dy,)][(SrIn2O4: Re3+ (Re = Pr, Tb, Dy)][Lu3Ga5O12:Re3+ (Re = Eu, TbPr)]Pr, Sm, Eu, Tb, Dy, TmSr2CeO4SiO2CaTiO3:Pr3+, Y3Al5O12:Ce3+/Tb3+/Ga2O3:Dy3+XRDFTIRSEMTEM(PL)(CL) (LaGaO3)(Eu3+, Tb3+, Dy3+, Tm3+, Sm3+)(Eu3+, Tb3+, Dy3+, Tm3+, Sm3+)LaGaO3: Eu3+LaGaO3: Dy3+LaGaO3: Tm3+LaGaO3: Sm3+LaGaO3: Sm3+,Tb3+LaGaO3: Tb3+Tb3+LaGaO3: Tb3+LaGaO3: Tm3+FED(Y2SiO5: Ce3+NP-1047)LaGaO3: Sm3+((Zn,Cd)S: AgNP-1020)(LaGaO3: Sm3+,Tb3+), [(LaGaO3: Re3+ (Re = Eu, Tb, Dy, Tm, Sm )] Sr/CaIn2O4Sr/CaIn2O4Pr3+/Tb3+/Dy3+Sr/CaIn2O4Pr3+/ Tb3+/Dy3+Pr3+/Tb3+/Dy3+Sr/CaIn2O4: Pr3+/Tb3+/Dy3+(CL)(PL)CL CaIn2O4:Eu3+CaIn2O4:Eu3+Eu3+ Lu3Ga5O12:Re3+ (Re = Eu, TbPr)UVLu3Ga5O12: Eu3+, Lu3Ga5O12: Pr3+Eu3+, Pr3+Lu3Ga5O12:Tb3+Tb3+ Sr2CeO4UV(Ce4+-O2-) SiO2@CaTiO3:Pr3+SiO2@Y3Al5O12: Ce3+/Tb3+, FESEMTEMSiO2UVSiO2@CaTiO3:Pr3+Pr3+ 1D23H4 (612 nm)SiO2@Y3Al5O12:Ce3+SiO2@Y3Al5O12:Tb3+ Ce3+5d-4fTb3+5D4-7FJ (J = 6, 5, 4, 3)PLCL Ga2O3:Dy3+-Ga2O3:Dy3+--Ga2O3Dy3+--Ga2O3:Dy3+
