The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with r...The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.展开更多
A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution...A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution, thermal stability and phase structure. The electrical conductivity of the samples was investigated by four-probe technique. With the increase of substituted-ionic radius, the temperature of phase formation increases, and the solid solubility decreases gradually, respectively. The La0.6Ca0.4FeO3-δ（LCF）powder is pure cubic perovskite-type crystalline after fired at 850℃ for 2 h. The XRD patterns of La0.6Sr0.4FeO3-δ（LSF） powder shows a small quantity of SrO peaks sintered at 1050℃ for 2 h. The electrical conductivity of LCF and LSF at 500 - 800℃ is over 100 S·cm^ - 1, and the value of LCF is 1170 S·cm^ - 1 at 800℃, which indicate that LCF and LSF may be used as a profitable cathode for IT-SOFCs. The characteristic of La0.6 Ba0.4FeO3-δ（LBF） is poor, and the electrical conductivity at intermediate temperatures is 1/20 less than that of LSF.展开更多
The europium ions doped MMoO4 （M=Sr, Ba） nanophosphors were successfully synthesized via a facile hydrothermal method using isopropanol. The relationship between phosphor crystalline phase, morphology, photohtminesc...The europium ions doped MMoO4 （M=Sr, Ba） nanophosphors were successfully synthesized via a facile hydrothermal method using isopropanol. The relationship between phosphor crystalline phase, morphology, photohtminescent properties and hexadecyl trimethyl ammonium bromide （CTAB） concentration, pH value in precursor solution was investigated. The results indi- cated that the morphology and photoluminescent properties were strongly influenced by CTAB concentration and pH value in precursor solution. In SrMoO4：Eu3＋ hosts, the phosphor surface tended to become smoother as the concentration of CTAB was increased; while particles tended to agglomerate as increasing pH value. The relative intensity ratio of charge transfer band to Eu3＋ characteristic emission peaks of MMoO4：Eu3＋ （M=Sr, Ba） was changed as CTAB concentration and pH value changed. The emission spectra of MMoO4：Eu3＋ （M=Sr, Ba） could be adjusted by CTAB concentration and pH value due to their impacts on the structure. It was im- portant that the different morphologies and photoluminescent properties of MMoO4：Eu3＋ （M=Sr, Ba） could be obtained by the facile hydrothermal method and modulated by changing CTAB concentration and pH value.展开更多
基金the National Natural Science Foundation of China (No. 51602126)the National Key Research and Development Plan of China (No. 2016YFB0303505)+1 种基金China and University of Jinan Postdoctoral Science Foundation (No. 2017M622118 and XBH1716)the 111 Project of International Corporation on Advanced Cement-based Materials (D17001).
文摘The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.
基金Project Supported bythe Natural Science Foundation of Bureau Education Anhui Province (N2004kj326)
文摘A series samples of La0.6M0.4FeO3-δ （M = Ca, Sr, process （GNP）. FTIR, TG-DSC, XRD and TEM techniques Ba） perovskite-type oxides were prepared by glycine nitrate were used to characterize the chemical constitution, thermal stability and phase structure. The electrical conductivity of the samples was investigated by four-probe technique. With the increase of substituted-ionic radius, the temperature of phase formation increases, and the solid solubility decreases gradually, respectively. The La0.6Ca0.4FeO3-δ（LCF）powder is pure cubic perovskite-type crystalline after fired at 850℃ for 2 h. The XRD patterns of La0.6Sr0.4FeO3-δ（LSF） powder shows a small quantity of SrO peaks sintered at 1050℃ for 2 h. The electrical conductivity of LCF and LSF at 500 - 800℃ is over 100 S·cm^ - 1, and the value of LCF is 1170 S·cm^ - 1 at 800℃, which indicate that LCF and LSF may be used as a profitable cathode for IT-SOFCs. The characteristic of La0.6 Ba0.4FeO3-δ（LBF） is poor, and the electrical conductivity at intermediate temperatures is 1/20 less than that of LSF.
基金Project supported by the Nation Natural Science Foundation of China(51562025)Graduate Student Innovation Special Funds(YC2016-S085)
文摘The europium ions doped MMoO4 （M=Sr, Ba） nanophosphors were successfully synthesized via a facile hydrothermal method using isopropanol. The relationship between phosphor crystalline phase, morphology, photohtminescent properties and hexadecyl trimethyl ammonium bromide （CTAB） concentration, pH value in precursor solution was investigated. The results indi- cated that the morphology and photoluminescent properties were strongly influenced by CTAB concentration and pH value in precursor solution. In SrMoO4：Eu3＋ hosts, the phosphor surface tended to become smoother as the concentration of CTAB was increased; while particles tended to agglomerate as increasing pH value. The relative intensity ratio of charge transfer band to Eu3＋ characteristic emission peaks of MMoO4：Eu3＋ （M=Sr, Ba） was changed as CTAB concentration and pH value changed. The emission spectra of MMoO4：Eu3＋ （M=Sr, Ba） could be adjusted by CTAB concentration and pH value due to their impacts on the structure. It was im- portant that the different morphologies and photoluminescent properties of MMoO4：Eu3＋ （M=Sr, Ba） could be obtained by the facile hydrothermal method and modulated by changing CTAB concentration and pH value.
基金Higher Educational Natural Science Foundation of Anhui Province(KJ2010A012)Open Foundation of Anhui Key Laboratory of Information Materials and Devices and the "211 Project" of Anhui University
