Luminescence Properties of (Y, Gd)Al_3(BO_3)_4∶Eu ~(3 ) under VUV excitation

Thephosphorsasanimportantpartofplasmadis playpanel (PDP)deviceemitvisiblelightundervac uumultraviolet (VUV)excitationof 14 7nmand/or172nmfromXe/Hegasplasma[1] .Untilrecently ,Y2 O3∶Eu3 and (Y ,Gd)BO3∶Eu3 havebeenusedascommercialred emittingphosphorsforPDP[2 - 3] .Butthesematerialsstillhaveshortcomingstobeim proved :lowlightoutputofY2 O3∶Eu3 uponVUVex citationandbadcolorpurityof (Y ,Gd )BO3∶Eu3 [4～ 5] .AluminoborateshavestrongabsorptionintheVUVregion ,andexhibitexcellentma…     

Synthesis and Luminescence Properties of Gd_2O_3∶Eu~(3+) Phosphors

Gd2 O3∶Eu3+ isanefficientredemittinglumines centmaterial ,whichcanbeappliedindisplays[1,2 ] .TheconventionalcommercialGd2 O3∶Eu3+ ismainlysynthesizedbyhightemperaturesolid statereactionandchemicalco precipitationmethods .Anadvancedperformanceofdisplaysrequireshighqualityphospho rssuchashighbrightnessandefficiency ,monodisper sityandfinegrainsize .Muchresearchhasanticipatedthatsubmicrometer sizedandnanometerluminescentmaterialswillhavethesepotentialadvantages[3～ 8] ,sosubmicrometer sizedan…     

Luminescence and Energy Transfer Properties of Ca_2Gd_8(SiO_4)_6O_2∶A(A=Pb~(2 ), Tm~(3 ))Phosphors

Compoundswiththeapatitestructureareverysuit ablehostlatticesforvariousluminescentions .ThemostwellknownexampleisSb3 andMn2 coactivatedcalci umhalophosphateCa5(PO4 ) 3(F ,Cl)∶Sb ,Mn ,whichhasfoundapplicationsinfluorescentlampsforalongtime[1] .Ca2 R8(SiO4 ) 6 O2 (R =Y ,Gd ,La)isakindofternaryrare earth metalsilicatewiththeoxyapatitestructure ,whichhasbeenusedashostmaterialsfortheluminescenceofvariousrareearthandmercury likeions[2～ 4 ] .Themostprominentstructuralcharacteristicisthetwos…     

九配位Sm3+,Eu3+和Gd3+与EDTA配合物的合成及结构研究

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.     

九配位Sm3+,Eu3+和Gd3+与EDTA配合物的合成及结构研究

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.     

Preparation,Structural Analysis and Luminescence Properties of Nanocrystalline Phosphor Gd2O3∶Eu

Nanocrystalline monoclinic and cubic Gd2O3∶Eu with different Eu3 concentration were prepared using glycine-nitrate combustion synthesis. By changing the ratio of glycine to nitrate and proper heat treatment, pure monoclinic and cubic Gd2O3∶Eu with particle size less than 40 nm can be easily formed. Under ultraviolet excitation, main emission of Eu3 (5D0→7F2) locates at 624 nm in monoclinic Gd2O3∶Eu and 611 nm in cubic sample. In excitation spectrum two broad bands corresponding to the host absorption and charge transfer state(CTS) and f-f transitions of Gd3 and Eu3 were observed and discussed. The quenching concentration of monoclinic and cubic Gd2O3∶Eu is 10% and 15%, respectively, both of which are much higher than that of bulk Gd2O3∶Eu.     

Gd3+,Eu3+在介孔Y2O3中的能量传递

通过模板法与溶胶-凝胶法相结合,在温和的条件下制备了介孔Y2O3.再采用水热反应法制得Eu3+、Gd3+单掺杂及Eu3+,Gd3+双掺杂的三种介孔Y2O3组装体(介孔Y2O3∶Eu3+,介孔Y2O3∶Gd3+,介孔Y2O3∶Eu3+,Gd3+).利用广角和小角X射线衍射(XRD)、透射电子显微镜(TEM)对介孔Y2O3进行了表征,结果表明,所制备的介孔Y2O3为立方相,具有六方孔道结构,孔径约10nm.对介孔Y2O3和组装体系进行了荧光光谱(PL)分析,发现在550℃热扩散处理后,介孔Y2O3∶Eu3+的发光存在基质对Eu3+的能量传递,Y2O3∶Eu3+,Gd3+体系中Gd3+对Eu3+也有能量传递作用.     

Synthesis and crystal structure of a 1D chainlike rare earth coordinated tungstogermenate： [（CH3）4N]1.50H3.50[Gd（GeW11O39）（H2O）2]·2.5H2O

A 1D zigzag polyoxometalate [(CH3)4N]1.50H3.50[Gd(GeW11O39)(H2O)2]·2.5H2O(1) was synthesized by reaction of the monova-cant polyanion [α-GeW11O39]8- with Gd3+ ions in aqueous solution and characterized by IR, UV spectra, ICP, and X-ray crystallography. X-ray single-crystal structural analysis indicated that the title compound crystallized in a monoclinic lattice, C2/c space group with α=2.8201(5), b=2.2885(3), c=2.4033(4) nm,β=123.875 (2)°, V=12.878(4) nm3, Z=8, R1=0.0623, wR2=0.1287. The solid-state structure of the title compound displayed an infinite one-dimensional arrangement built up of [α-GeW11O39]8- polyanions connected by GdⅢ cations.     

Preparation and Luminescence Properties of the New Long Phosphorescent Phosphors Ba_(1-x)Ca_xAl_2O_4∶Eu ~(2 ), Dy~(3 )

Inrecentyears ,SrAl2 O4 ∶Eu2 ,Dy3 ,CaAl2 O4 ∶Eu2 ,Nd3 [1～ 8] andBaAl2 O4 ∶Eu2 ,Dy3 [9]havebeenconsideredasusefulblueandgreenphos phorsbytheirlongdurationphosphorescence .Howev er ,toourknowledge ,thephosphorBa1-xCaxAl2 O4 ∶Eu2 ,Dy3 hasnotbeeninvestigated .TheluminescenceofEu2 isverystronglydepen dentonthehostlattice ,whichcanoccurfromtheul traviolettotheredregionoftheelectromagneticspec trum .Itiswellknownthatthepersistentluminescenceisduetothetrappingofenergyinthed…     

A New Yellow Long Lasting Phosphor Y_2O_2S∶Ti

Longphosphorescencephosphorshaveattractedconsiderableattentioninrecenthalf century[1] becauseoftheirpotentialapplicationsinsuchfieldsaslumi nouspaint ,safetyindicatorinemergencycase ,etc[2～ 4 ] .Sincethediscoveryofalkali earthaluminatelonglastingphosphorsin 1996 [1] ,theyhavebeenstudiedextensivelyastheyhavebetterstabilityandlongerpersistenttimethanthesulfidephosphorswhichwerewidelyusedinmanycases .Uptonow ,poly crystallinephosphorsofblueCaAl2 O4 ∶ (Eu2 ,Nd3 ) ,greenSrAl2 O4 ∶(Eu2 ,…     

Synthesis and Spectral Properties of Nd~(3+)∶Gd_3Ga_5O_(12) Nanopowder for Transparent Laser Ceramics

Recently ,ceramicsforlaser mediumhas receivedonsiderable attention . By sintering ceramics , it isossible to overcome the disadvantages of growing sin-le crystal such as high cost , long manufacturingi me , and low doping ratio . A novel technology[1 ~5]as been adoptedto produce hightransparent ceramicswithsufficiently lowscattering loss and high laser os-illation. Nd3 +∶Gd3Ga5O12[6 ~9]has high fracturetrength, good chemical stability , high thermal con-uctivity,large rare earth doping ratio…     

Study on Spectra of La_2CaB_(10)O_(19)∶Eu~(3 ) in VUV-VIS Range

Manyboratesareexcellenthostsforrareearthlu minescence ,forexample ,nowbestredphosphorinplasmadisplaypanel (PDP )is (Y1-xGdx)BO3∶Eu[1] .Boratephosphorsdopedwithrareearthionshavebeenrichlystudiedinthepastfewdecades[2 ,3] .RecentlyWuYichengetal .[4 ] synthesizedanewbo rateLa2 CaB10 O19,whichispotentialnonlinearopticalmaterials.InthisworkweselectedLa2 CaB10 O19ashostofluminescencematerialsbecauseitprobablyisabetterhostforrareearthluminescence .Duetotherequirementofplasmadisplaypenal(PDP)…     

Sensitive and fast response ethanol chemical sensor based on as-grown Gd2O3 nanostructures

Well crystalline gadolinium oxide(Gd2O3) nanostructures were grown by annealing the hydrothermally as-prepared nanostructures without using any template. Microscopic studies of Gd2O3 nanostructures were recorded along the [111] direction due to the clearly resolved interplanar distance d(222)~0.31 nm of the cubic crystal structure Gd2O3. Sensing mechanism of Gd2O3 as efficient electron mediator for the detection of ethanol was explored. As-fabricated sensor demonstrated the high-sensitivity of ~0.266 μAm/M/cm2 with low detection limit(~52.2 μmol/L) and correlation coefficient(r2, 0.618). To the best of our knowledge, this was the first report for the detection of ethanol using as-grown(at 1000 oC) Gd2O3 nanostructures by simple and reliable I-V technique and rapid assessment of the reaction kinetics(in the order of seconds). The low cost of the starting reagents and the simplicity of the synthetic route made it a promising chemical sensor for the detection of various toxic analytes, which are not environmentally safe.     

镧系元素磷钒杂多酸盐的合成与表征

首次合成了具有bicapped-Keggin型结构[PV14O42]9-阴离子的四种稀土盐:H1.5Ln2.5[PV14O42]·nH2O(Ln=La3 、Ce3 、Pr3 、Gd3 ),并用化学分析、IR、UV、TG、摩尔电导等方法对其进行了表征。结果表明,四种稀土盐处于杂多阴离子[PV14O42]9-的外界,并且[PV14O42]9-仍基本保持着bicapped-Keggin型结构。     

Synthesis,crystal structure and photocatalytic performance of polyoxometalate K_(13)[Gd(GeW_(11)O_(39))_2]·34H_2O

A polyoxometalate K_(13)[Gd(GeW_(11)O_(39))_2]·34 H_2 O was synthesized and characterized by elemental analysis,IR spectroscopy, UV spectra, XRD and thermal gravimetric analysis. X-ray single-crystal structural analysis indicates that the title compound crystallizes in the triclinic crystal system. The heteropolyanion of [Gd(GeW_(11)O_(39))_2]~(13) consists of two [GeW_(11)O_(39)]~(8-) vacant Keggin moieties linked via Gd~(3+). Photocatalytic performance of K_(13)[Gd(GeW_(11)O_(39))_2]·34 H_2 O in photodegradation of X-3 B was also studied.When the reaction time is 180 min, the decoloring rate reaches 71.19%. With the decrease of pH, the decolorization rate increases gradually.     

SrAl_2O_4∶Eu~(2+),Nd~(3+) and Dy~(3+) Long Afterglow Phosphor

Longafterglowphosphorabsorbingenergyfromsolar,lampandotherlightsourcesforashorttimestorestheenergyandexhibitsbrightandlong lastingphosphorescencewhichsuitsthevisualperceptionofthehumaneyewithminimumbrightness 0 32mcd·m- 2 andlastingtimemorethan 8h) .TheSrAl2 O4 ∶Eu2 +,Dy3+phosphorhasbeenknowntobeagreenlongafterglowphosphorwithanemissionpeakat 5 2 0nm[1～ 7] .ThepropertiesofthephosphorwerefurtherexaminedbythegroupofTangMingdaoandMatsuzawaTindetailin 1995and 1996respectively[1,2 ] .Inorde…     

Syntheses of Alkaline Earth and Lanthanide Cryptates with Pyridine-Based Group

New alkaline earth metal cryptates [ML]（NO3）2 ·2H2O （M=Ca^2＋, Sr^2＋, Ba^2＋; L = 1, 4,12,15,18, 26, 31, 39, 42, 43, 44-undecaazapentacyclo- [ 13.13.13.1^6,10 .1^20,24 .1^33,37 ]-tetratetraconta -4, 6, 8, 10（44）, 11, 18, 20, 22, 24（43）, 25, 31, 33, 35, 37（42）, 38-pentadecaene） were synthesized by [2 ＋ 3 ] template condensation of tris（2-aminoethyl） amine with 2, 6-diformylpyridine, and then by transmetallation reactions of the calcium cryptate [CaL] （NO3）2·2H2O with corresponding lanthanide ions; three lanthanide cryptates [ LnL] （NO）3·3H2O （Ln = Eu, Gd, Tb） were synthesized and characterized by physical methods. The crystal structure of the terbium cryptate [TbL] （NO）3·3H2O was studied by X-ray analysis. The central atom was coordinated by three pyridyl and six imino nitrogen atoms and exhibited a distorted tricapped trigonal prismatic coordination geometry.     

铽在硫氧化镧基质中的光致发光

采用高温固相反应法制备了La2O2S∶Tb3+、La2O2S∶Tb3+,RE3+(RE=Dy,Gd,Ce,Sm)荧光粉样品并进行了相关表征。结果表明,合成样品的晶体结构与La2O2S相同,为六方晶系;荧光粉颗粒的形貌多为长方形片状;发射光谱由494 nm、545 nm、587 nm、622 nm的一系列锐发射峰组成。研究发现Tb3+的掺杂浓度对样品主发射峰545 nm的发光强度影响很大,且在摩尔分数x(Tb3+)=0.02时达到最强。稀土离子Dy3+、Gd3+对La2O2S∶Tb3+荧光粉的发光有明显的敏化作用。     

GdCl3-Gd2O3膨胀石墨复合材料的制备及表征

以氯化钆( GdCl3)饱和溶液作为钆源,膨胀石墨(EG)为载体,利用化学浸渍法合成了GdCl3为3阶、Gd2O3为4阶的混合结构式GdCl3-Gd2 O3-EG复合材料.通过FESEM、EDS和XRD对产物的形貌、成分和阶结构进行表征,结果表明,当原料mGd2O3/mEG(质量比)较小时,GdCl3 -EG为2、3阶混合结构,随着质量比的增大,插层结构稳定为3阶结构；同时,Gd3+与膨胀石墨中的含氧基团结合生成Gd2O3,Gd2O3进入膨胀石墨层间形成4阶结构的Gd2 O3-EG,其阶结构不随mGd2O3/mEG比值的变化而变化.     

Vacuum ultraviolet excited photoluminescence properties of Gd2O2CO3：Eu^3＋ phosphor

The Gd2O2CO3：Eu^3＋ with type-Ⅱ structure phosphor was successfully synthesized via flux method at 400 ℃ and their photoluminescence properties in vacuum ultraviolet （VUV） region were examined. The broad and strong excitation bands in the range of 153-205 nm owing to the CO3^2- host absorption and charge transfer （CT） of Gd^3＋-O2^- were observed for Gd2O2CO3：Eu^3＋. Under 172 nm excitation, Gd2O2CO3：Eu^3＋ exhibited strong red emission with good color purity, indicating Eu^3＋ ions located at low symmetry sites and the chromaticity coordination of luminescence for Gd2O2CO3：Eu^3＋ was （x=0.652, y=0.345）. The photoluminescence quenching concentration of Eu^3＋ excited by 172 nm for Gd2O2CO3：Eu^3＋ was about 5%. Gd2O2CO3：Eu^3＋ would be a potential VUV-excited red phosphor applied in mercury-free fluorescent lamps.