The structure of the low-temperature 4f^N→4f^N-15d excitation spectra of Eu^3＋ and Tb^3＋ doped in crystals LiYF4, YPO4 and CaF2 measured by van Pieterson et al. in 2002 was analyzed and assigned based on the simple...The structure of the low-temperature 4f^N→4f^N-15d excitation spectra of Eu^3＋ and Tb^3＋ doped in crystals LiYF4, YPO4 and CaF2 measured by van Pieterson et al. in 2002 was analyzed and assigned based on the simple model proposed by Duan and co-workers in the last few years. Some complemental discussion on effects of J-mixing on the f-d transition intensities for Eu^3＋ due to the f-electron crystal-field interaction Hcf（f）, which was ignored in the simple mod- el, was presented. Some previously unexplained peaks for Tb^3 ＋ were interpreted to be spin-forbidden transitions to higher 5d crystal-field levels, or assigned to be f→d excitations with the core 4f7 excited from ^8S to ^6P, ^6I and ^6D, respectively. It is shown that the main structure of 4f-Sd excitation spectra of Eu^3＋ and Tb^3＋ can be well interpreted with the simple model.展开更多
The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that cr...The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that crystal structure of CaS has formed at 700 ℃. Spectrum analysis results show that the samples which were stimulated by 980 nm laser after excited by ultraviolet lamp emit red luminescence peaking at 649 nm.展开更多
镧系金属有机骨框架(Lanthanide metal organic frameworks,Ln-MOFs)是以镧系离子为中心,与配体有机物组合的多孔材料,具有良好的光学性质,在许多领域有广泛的应用。不同的镧系离子与相应的有机配体结合,可组成不同性能的Ln-MOFs。在众...镧系金属有机骨框架(Lanthanide metal organic frameworks,Ln-MOFs)是以镧系离子为中心,与配体有机物组合的多孔材料,具有良好的光学性质,在许多领域有广泛的应用。不同的镧系离子与相应的有机配体结合,可组成不同性能的Ln-MOFs。在众多镧系元素中,Tb^(3+)和Eu^(3+)是良好的发光中心,常被用于组建发光Ln-MOFs。由Tb^(3+)/Eu^(3+)与有机配体形成的Ln-MOFs具有独特的荧光特性、较大Stokes位移以及长发光寿命等优点,在荧光检测领域具有重要应用。综述了基于Tb^(3+)/Eu^(3+)的Ln-MOFs在离子检测、生物标志物检测以及小分子检测领域的研究进展,并对Ln-MOFs的发展前景进行了展望。展开更多
Gd 2O 3∶Eu 3+ phosphors were prepared by urea homogeneous precipitation with different surfactant and sol-gel method. XRD patterns show that all the obtained samples are in cubic Gd 2O 3, and the results of FTIR...Gd 2O 3∶Eu 3+ phosphors were prepared by urea homogeneous precipitation with different surfactant and sol-gel method. XRD patterns show that all the obtained samples are in cubic Gd 2O 3, and the results of FTIR and fluorescent spectra conformed that OP is a good surfactant for preparing the Gd 2O 3∶Eu 3+ phosphors. The SEM photographs show that the particles prepared by urea homogeneous precipitation method are all spherical and well-dispersed, and grain morphology can be controlled by different surfactant. XRD and SEM indicate that the particle sizes prepared by sol-gel method are in the range of 5～30 nm, and the grain sizes increase with increasing of heated temperatures. Luminescence spectra indicat that the main emission peaks of all samples are at 610 nm, the intensities are different from samples prepared with different surfactant and the luminescence intensities increase with increasing of annealed temperatures.展开更多
New long phosphorescent phosphors Ba 1-xCa xAl 2O 4∶Eu 2+, Dy 3+ with tunable color emission were prepared and studied. The emission spectra show that the tuning range of the color emission of the phosphors i...New long phosphorescent phosphors Ba 1-xCa xAl 2O 4∶Eu 2+, Dy 3+ with tunable color emission were prepared and studied. The emission spectra show that the tuning range of the color emission of the phosphors is between 498 and 440 nm, which is dependent on x, under the excitation of UV. The wavelength of the afterglow increases with the increasing of x until x equals 0.6. The XRD patterns show that the single phase limit in the phosphors is below x value of 0 4. The Thermoluminescence spectra were measured to investigate the traps created by the doping of Dy 3+.展开更多
Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and the...Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...展开更多
The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, UV-vis diffuse ...The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, UV-vis diffuse reflectance spectrum, and photoluminescence spectra.The results of XRD indicated that the obtained LaF3：Eu^3＋ nanoparticles were well crystallized with a hexagonal structure.The FE-SEM image illustrated that the LaF3：Eu^3＋ nanoparticles were spherical with an average size around 30 nm.Under irradiation of UV light, the emission spectrum of LaF3：Eu^3＋ nanoparticles exhibited the characteristic line emissions arising from the 5D0→7FJ（J=1, 2, 3, 4） transitions of the Eu3＋ ions, with the dominating emission centered at 590 nm.In addition, the emissions from the 5D1 level could be clearly observed due to the low phonon energies（-350 cm^-1） of LaF3 matrix.The optimum doping concentration for LaF3：Eu3＋ nanoparticles was determined to be 20mol.%.展开更多
The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis ...The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis and FTIR. The results of the XRD patterns and SEM photographs indicate that the complex is composed of a lot of bar-shaped crystal grain with 5～10 μm long. The results of the photoluminescence show that the complex emitted the characteristic green fluorescence of Tb (3+).展开更多
A type of red luminescent Sr3Al2O6：Eu2＋, Dy3＋ phosphor powder is synthesised by sol-gel-combustion processing, with metal nitrates used as the source of metal ions and citric acid as a chelating agent of metal ions...A type of red luminescent Sr3Al2O6：Eu2＋, Dy3＋ phosphor powder is synthesised by sol-gel-combustion processing, with metal nitrates used as the source of metal ions and citric acid as a chelating agent of metal ions. By tracing the formation process of the sol-gel, it is found that it is necessary to reduce the amount of NO3 by dropping ethanol into the solution for forming a stable and homogeneous sol-gel. Thermogravimetric and Differential Scanning Calorimeter Analysis, x-ray diffractionmeter, scanning electron microscopy and photoluminescence spectroscopy are used to investigate the luminescent properties of the as-synthesised Sr3A1206：Eu2＋, Dy3＋. The results reveal that the Sr3Al2O6 crystallises completely when the combustion ash is sintered at 1250℃. The excitation and the emission spectra indicate that the excitation broadband lies mainly in a visible range and the phosphors emit a strong light at 618 nm under the excitation of 472 nm. The afterglow of （Sr0.94Eu0.03Dy0.03）3Al2O6 phosphors sintered at 1250℃ lasts for over 1000 s when the excited source is cut off.展开更多
Green-photoluminescence material Zn4B6O13: Ce3+, Tb3+ was first synthesized by spread method of high temperature and solid state reaction, which is cubic crystal system with lattice parameters: a(0) = 0.7472 nm, V = 0...Green-photoluminescence material Zn4B6O13: Ce3+, Tb3+ was first synthesized by spread method of high temperature and solid state reaction, which is cubic crystal system with lattice parameters: a(0) = 0.7472 nm, V = 0.4172 nm(3), and structural properties are investigated by XRD. The excitation and emission band of Ce3+ ion single-doped in Zn4B6O13 transfer longer spectra 2.38 similar to 4.94 kk than in other matrices. Emission band of Ce3+ ion better overlaps with the F-7(6)-->(5)G(2),D-5(1),H-5(7) absorption band of Tb3+. It shows that emission of Tb3+ ion is sensitized by Ce3+. In Zn4B6O13:Ce3+, Tb3+, it is due to the energy transfer mechanism, resonance transfer of electric multipolar interaction of the dipole-dipole between Ce3+-->Ce3+ and Ce3+-->Tb3+. The color coordinates of Zn4B6O13: X 0.281, gamma = 0.619. The mean diameter of the particles is 0.23 mum.展开更多
文摘The structure of the low-temperature 4f^N→4f^N-15d excitation spectra of Eu^3＋ and Tb^3＋ doped in crystals LiYF4, YPO4 and CaF2 measured by van Pieterson et al. in 2002 was analyzed and assigned based on the simple model proposed by Duan and co-workers in the last few years. Some complemental discussion on effects of J-mixing on the f-d transition intensities for Eu^3＋ due to the f-electron crystal-field interaction Hcf（f）, which was ignored in the simple mod- el, was presented. Some previously unexplained peaks for Tb^3 ＋ were interpreted to be spin-forbidden transitions to higher 5d crystal-field levels, or assigned to be f→d excitations with the core 4f7 excited from ^8S to ^6P, ^6I and ^6D, respectively. It is shown that the main structure of 4f-Sd excitation spectra of Eu^3＋ and Tb^3＋ can be well interpreted with the simple model.
文摘The CaS∶Eu^(2+), Sm^(3+) powders were prepared by high-temperature solid method in a reducing atmosphere. The influences of temperature and fired-time on properties of samples were studied. XRD analysis shows that crystal structure of CaS has formed at 700 ℃. Spectrum analysis results show that the samples which were stimulated by 980 nm laser after excited by ultraviolet lamp emit red luminescence peaking at 649 nm.
文摘镧系金属有机骨框架(Lanthanide metal organic frameworks,Ln-MOFs)是以镧系离子为中心,与配体有机物组合的多孔材料,具有良好的光学性质,在许多领域有广泛的应用。不同的镧系离子与相应的有机配体结合,可组成不同性能的Ln-MOFs。在众多镧系元素中,Tb^(3+)和Eu^(3+)是良好的发光中心,常被用于组建发光Ln-MOFs。由Tb^(3+)/Eu^(3+)与有机配体形成的Ln-MOFs具有独特的荧光特性、较大Stokes位移以及长发光寿命等优点,在荧光检测领域具有重要应用。综述了基于Tb^(3+)/Eu^(3+)的Ln-MOFs在离子检测、生物标志物检测以及小分子检测领域的研究进展,并对Ln-MOFs的发展前景进行了展望。
文摘Gd 2O 3∶Eu 3+ phosphors were prepared by urea homogeneous precipitation with different surfactant and sol-gel method. XRD patterns show that all the obtained samples are in cubic Gd 2O 3, and the results of FTIR and fluorescent spectra conformed that OP is a good surfactant for preparing the Gd 2O 3∶Eu 3+ phosphors. The SEM photographs show that the particles prepared by urea homogeneous precipitation method are all spherical and well-dispersed, and grain morphology can be controlled by different surfactant. XRD and SEM indicate that the particle sizes prepared by sol-gel method are in the range of 5～30 nm, and the grain sizes increase with increasing of heated temperatures. Luminescence spectra indicat that the main emission peaks of all samples are at 610 nm, the intensities are different from samples prepared with different surfactant and the luminescence intensities increase with increasing of annealed temperatures.
文摘New long phosphorescent phosphors Ba 1-xCa xAl 2O 4∶Eu 2+, Dy 3+ with tunable color emission were prepared and studied. The emission spectra show that the tuning range of the color emission of the phosphors is between 498 and 440 nm, which is dependent on x, under the excitation of UV. The wavelength of the afterglow increases with the increasing of x until x equals 0.6. The XRD patterns show that the single phase limit in the phosphors is below x value of 0 4. The Thermoluminescence spectra were measured to investigate the traps created by the doping of Dy 3+.
基金supported by the National Natural Science Foundation of China (10704090, 10874253)Foundation of the Education Committee of Chongqing (10874173)
文摘Ce3+,Eu3+ and Tb3+ singly doped and Ce3+/Eu3+ and Ce3+/Tb3+ co-doped zinc phosphate glasses were prepared by sintering P2O5,ZnO,Ce2(C2O4)3·10H2O and Eu2O3/Tb4O7 mixtures at 1200 °C in the air for 2 h and then annealing at 450 °C for 10 h.The obtained glasses were homogeneous and transparent.The glasses without Ce3+ were colorless and those with Ce3+ showed slightly yellow.The singly doped glasses showed strong emissions and excitations from doped trivalent rare earth ions.Strong energy transfer from Ce3+ to...
基金supported by the Natural Science Foundation of Henan Province (082300440130, 2008A180039, 2007150049)Startup Fund for Doctoral Program of Zhoukou Normal University
文摘The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction（XRD）, field emission scanning electron microscopy（FE-SEM）, UV-vis diffuse reflectance spectrum, and photoluminescence spectra.The results of XRD indicated that the obtained LaF3：Eu^3＋ nanoparticles were well crystallized with a hexagonal structure.The FE-SEM image illustrated that the LaF3：Eu^3＋ nanoparticles were spherical with an average size around 30 nm.Under irradiation of UV light, the emission spectrum of LaF3：Eu^3＋ nanoparticles exhibited the characteristic line emissions arising from the 5D0→7FJ（J=1, 2, 3, 4） transitions of the Eu3＋ ions, with the dominating emission centered at 590 nm.In addition, the emissions from the 5D1 level could be clearly observed due to the low phonon energies（-350 cm^-1） of LaF3 matrix.The optimum doping concentration for LaF3：Eu3＋ nanoparticles was determined to be 20mol.%.
文摘The luminescent complex of Tb (3+)-trimesic acid was synthesized in an alcohol and water mixed solvent. The chemical components of the complex TbL·5H_2O was characterized by the element analysis,thermal analysis and FTIR. The results of the XRD patterns and SEM photographs indicate that the complex is composed of a lot of bar-shaped crystal grain with 5～10 μm long. The results of the photoluminescence show that the complex emitted the characteristic green fluorescence of Tb (3+).
基金Project supported by the Key Research Project of Science and Technology of Shanxi, Shanxi Province, China (Grant No 2007031141)the Natural Science Foundation of Shanxi Province, China (Grant No 2007011061)the Scientific Research Foundation of the Higher Education Institutions of Shanxi Province, China (Grant No 20080012)
文摘A type of red luminescent Sr3Al2O6：Eu2＋, Dy3＋ phosphor powder is synthesised by sol-gel-combustion processing, with metal nitrates used as the source of metal ions and citric acid as a chelating agent of metal ions. By tracing the formation process of the sol-gel, it is found that it is necessary to reduce the amount of NO3 by dropping ethanol into the solution for forming a stable and homogeneous sol-gel. Thermogravimetric and Differential Scanning Calorimeter Analysis, x-ray diffractionmeter, scanning electron microscopy and photoluminescence spectroscopy are used to investigate the luminescent properties of the as-synthesised Sr3A1206：Eu2＋, Dy3＋. The results reveal that the Sr3Al2O6 crystallises completely when the combustion ash is sintered at 1250℃. The excitation and the emission spectra indicate that the excitation broadband lies mainly in a visible range and the phosphors emit a strong light at 618 nm under the excitation of 472 nm. The afterglow of （Sr0.94Eu0.03Dy0.03）3Al2O6 phosphors sintered at 1250℃ lasts for over 1000 s when the excited source is cut off.
文摘Green-photoluminescence material Zn4B6O13: Ce3+, Tb3+ was first synthesized by spread method of high temperature and solid state reaction, which is cubic crystal system with lattice parameters: a(0) = 0.7472 nm, V = 0.4172 nm(3), and structural properties are investigated by XRD. The excitation and emission band of Ce3+ ion single-doped in Zn4B6O13 transfer longer spectra 2.38 similar to 4.94 kk than in other matrices. Emission band of Ce3+ ion better overlaps with the F-7(6)-->(5)G(2),D-5(1),H-5(7) absorption band of Tb3+. It shows that emission of Tb3+ ion is sensitized by Ce3+. In Zn4B6O13:Ce3+, Tb3+, it is due to the energy transfer mechanism, resonance transfer of electric multipolar interaction of the dipole-dipole between Ce3+-->Ce3+ and Ce3+-->Tb3+. The color coordinates of Zn4B6O13: X 0.281, gamma = 0.619. The mean diameter of the particles is 0.23 mum.
