首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 46 毫秒
1.
Ternary complexes of europium and terbium with benzoic acid and 1, 10-phenanthroline [RE(BA)3phen] (BA=benzoate phen=1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid-state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.  相似文献   

2.
The (Ba1- x, Srx ) 2 SiO4 : EU^2+ green-emitting phosphors were synthesized by conventional solid-state reaction in a CO-reductive atmosphere, and their luminescent properties were investigated. The XRD data show that the Ba/Sr ratio not only affects the lattice parameters, but also influences the emission peak. The excitation spectra indicate that this phosphor can be effectively excited by UV light from 370 to 470 nm. The emission band is due to the 4f^65d^1→4f^7 transition of the Eu^2+ ion. With an increase in x, the emission band shifts to longer wavelength and the reason was discussed. The emission spectra exhibit a satisfactory green performance under different excitation wavelength(380,398,412,420,460 nm). (Ba1- x, Srx ) 2 SiO4 : EU^2+ is a promising phosphor for green white-lighting-emission diode by ultraviolet chip.  相似文献   

3.
The photoluminescence properties of BiTaO4:Pr^3 and BiTaO4 at room temperature were studied, and the infrared transmission and diffusion reflection spectra of BiTaO4 were measured. The photoluminescence spectrum of BiTaO4 peaks at about 420, 440 and 465nm. There has an obvious excitation band from 330 to 370nm. The photoluminescence spectrum of BiTaO4:Pr^3 consists of the characteristic emission of Pr^3 , and its main peak is at 606 nm from ^3P0→^3H6 transition of Pr^3 . Its excitation spectrum consists of the wide band with maximum at 325nm, the wide band in the range of 375-430nm, and the characteristic excitation of Pr^3 .The bands at 325nm and 375-430nm may be from the absorption of the charge transfer transition of the tantalate group and defect energy levels in its forbidden band, respectively.There is energy transfer from host to Pr^3 . Because both the host density and photoluminescence peak intensity of BiTaO4:Pr^3 are superior to PbWO4, BiTaO4:Pr^3 may be a potential heavy scintillator.  相似文献   

4.
5.
Tb^3 -doped CaxSr1-xWO4 was prepared by solid state reaction and characterized by powder X-ray diffractometry. According to X-ray diffraction, this material belongs to tetragonal system, which is consistent with space group 141/α. Lattice parameters in the systems CaxSr1-xWO4 were found to vary linearly with compositions. The emission and excitation spectra were measured. The miscibility, luminescence properties of Tb^3 -doped CaxSr1-xWO4 and energy transfer mechanism were discussed.  相似文献   

6.
Nominal composition of Ca1-xZnxTiO3 : 0. 002Pr^3 + (x = 0. 000 - 0. 200) phosphors were prepared by conventional solid reaction route. XRD and PL measurements were used to investigate the solid-solution structure and luminescence properties of Zn-doped Ca1-xZnxTiO3:0.002Pr^3+ phosphors. The effect of solid-solution structure formed by substitution between Ca^2 + and Zn^2+ ions on the luminescent properties was analyzed. The results reveal that, with the increase of Zn substitution content below 0.010, lattice parameters and the intensity of excitation peak at both 260 and 330 nm as well as the corresponding 610 nm emission intensity are monotonously decreased quickly in a similar tendency. Also, the evolution of luminescence intensity and crystal cell parameters against Zn doping concentration are in good agreement. Above results are closely related with the structure change within Ca1- xZnxTiO3:0.002Pr^3+ solid-solution phase formed by the Zn ions substitution for the Ca sites. Present study reveals that the solid-solution structure formed by substitution between Ca^2+ and Zn^2+ ions has significant effect on the luminescence properties of single phase Ca1-xZnxTiO3:0.002Pr^3+ phosphors.  相似文献   

7.
2 mercaptobenzothiazolewasfirstreportedbyHofmann[1 ] in 1 887.Ithasbeenusedasanacceleratorinthevulcanizationofrubberformanyyears .Todayitisstillbeingusedasamainacidicacceleratorinrubberindustry .Butithasdisadvantagesofvulcanizationreversionandeasyscorch[2 ] whe…  相似文献   

8.
In order to combine the merits of rare earth organic complexes with excellent material performances of polymers,a polymerizable chelating agent, 3-allyl-2, 4-pentane dione (APD), was synthesized by phase transfer catalysis and its rare earth complexes were prepared. The compounds were characterized by EA, IR and ^1H NMR. Their UV spectra and fluorescence spectra were investigated. The effects of allyl on the luminescence properties of the complexes were studied.The results show that the sensitization of APD is changed by allyl in comparison with that of acetyl acetone (acac), and it becomes an ideal novel ligand of Eu. In addition, intramolecular energy transfer mechanism in the luminescence process in the complexes was also discussed in detail.  相似文献   

9.
Thermal stimulated luminescence (TSL) and photostimulated luminescence (PSL) were used to investigate the luminescent performance of Al^3 -doped BaFBr:Eu^2 in different synthetic conditions. Theory analysis shows that the decay of TSL spectra is different from that of PSL spectra. Theoretical calculation was used to investigate the effects of energy state in Al^3 -doped BaFBr:Eu^2 by different synthetic conditions. The relationship of color center‘s energy and different synthetic conditions is discussed.  相似文献   

10.
Thelanthanidecomplexesoforganiclig andsasfluorescentmaterialshavereceivedex tensiveattention .Theuseoffluorescentorgano lanthanidecomplexesrequirehighfluo rescenceintensityandlowcostcomplexes .Inrecentyears ,thefluorescenceenhancementofTb(Ⅲ )orEu(Ⅲ )complexe…  相似文献   

11.
The effects of lanthanides at various concentrations on CaCO3 crystal growth were studied by X-ray diffraction (XRD), infrared spectra (IR), X-ray photoelectric energy spectra (XPS) and inductively coupled plasma mtms spectrometry (ICP-MS). It was found that the calcite, a stable form of CaCO3 in thermodynamics, is the predominant species. The research indicates that lanthanide ions (Ln3 ) can partly substitute the Ca2 in the lattice of CaCO3 crystals, and change the crystal characterization and direct the ordinal growth of CaCO3 crystals.  相似文献   

12.
13.
ResearchonF- containingwastewatertreatmenthasbeenpaidgreatattentionbecauseitcanseriouslyharmbodyiffluorioncontentexceedspermittedlimit .Methodstotreatfluorion containingwastewaterarebasedon :adsorption ,reverseosmosis ,ionexchangeresin ,chemicalprecipitation ,coagulatingprecipita tion[1] ,etc .Amongthesemethods ,adsorptionismostwidelyusedtoremovefluorionforitshighefficiency ,easypreparingprocess ,cheaprawmaterial ,andothermerits .Duringmanydefluoridationmaterials ,rareearthcompoundsattackmore…  相似文献   

14.
掺杂稀土氧化物的ZnO材料的制备及气敏性能   总被引:12,自引:1,他引:12  
牛新书  杜卫平  杜卫民  蒋凯 《稀土》2003,24(6):44-47
采用溶胶-凝胶法制备了ZnO及掺杂Y2O3、La2O3、CeO2的ZnO纳米微粒。利用X射线衍射仪、透射电镜对材料的结构进行了表征。研究了不同掺杂对材料的气敏性能的影响。研究表明,在工作温度305℃时,掺入质量分数为8%的CeO2后,材料对H2S气体有很好的灵敏度和选择性及较好的响应-恢复特性。并对气敏机理进行了探讨。  相似文献   

15.
详细报道了Sm3+,Eu3+和Gd3+分别与乙二胺四乙酸(EDTA)配体形成配合物的合成及结构测定.通过单晶X-射线衍射仪和元素分析的测定,确定了这些配合物的结构都是以Sm3+,Eu3+和Gd3+为中心的九配位单帽四方反棱柱体结构,组成分别为Na[Sm(EDTA)(H2O)3]·5H2O,Na[Eu(EDTA)(H2O)3]·4H2O和Na[Gd(EDTA)(H2O)3]·5H2O.  相似文献   

16.
Organic electroluminescence (OEL) has been ex-tensively studied owing to its potential application inflat panel displays ever since the first double-layerOELdevice that has high efficiency and luminescencewas fabricated in 1987[1 ~4]. When compared withcommon smaller organic molecules and polymers ,rareearth (RE) complexes exhibit extremely sharp , well-defined spectral lines due to the emissions that origi-nate fromthe lanthanide metal ions .So the electrolu-minescence (EL) of REcomplexes…  相似文献   

17.
18.
Red phosphor (Y, Gd)BO3:Eu3+ with grain shape, small size, non-agglomerate, high crystallinity and good photoluminescence (PL) intensity was prepared by a complex method that the precursor of the phosphor was prepared by co-precipitation method and the phosphor was prepared by combustion method. The SEM photos and the photoluminescence spectrum excited under VUV show that the morphology and luminescent properties of this phosphor are satisfied when an appropriate amount of urea was adopted as the combustion agent in the preparation procedure.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号