学科分类
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11 个结果
  • 简介:15%Ag-addedcubicperovskitesSr0.9La0.1TiO3andRuddlesden-Popper(RP)phasesSr2.7La0.3Ti2O7werefabricatedviahydrothermalsynthesis,coldpressingandhigh-temperaturesintering.Thestructureandthermoelectricpropertieswerealsoinvestigatedforallsamples.TheresultsindicatedthatAgprecipitatedasasecondphase.AgadditionmadeelectricalconductivityandabsoluteSeebeckcoefficientenhanced,asaresult,theZTvalueswereenhancedbothfortwoseries.Comparedwithcubicperovskite,RPphasewassubjectedtosmallerimpactbyAgaddition.ThereasonsforenhancingZTvalueandthedifferentimpactfortwoseriesbyAgadditionwerealsodiscussed.

  • 标签: 热电性能 SEEBECK系数 Ag 钙钛矿相 水热合成法 高温烧结
  • 简介:TheeuropiumionsdopedMMoO_4(M=Sr,Ba)nanophosphorsweresuccessfullysynthesizedviaafacilehydrothermalmethodusingisopropanol.Therelationshipbetweenphosphorcrystallinephase,morphology,photoluminescentpropertiesandhexadecyltrimethylammoniumbromide(CTAB)concentration,pHvalueinprecursorsolutionwasinvestigated.TheresultsindicatedthatthemorphologyandphotoluminescentpropertieswerestronglyinfluencedbyCTABconcentrationandpHvalueinprecursorsolution.InSrMoO_4:Eu~(3+)hosts,thephosphorsurfacetendedtobecomesmootherastheconcentrationofCTABwasincreased;whileparticlestendedtoagglomerateasincreasingpHvalue.TherelativeintensityratioofchargetransferbandtoEu~(3+)characteristicemissionpeaksofMMoO_4:Eu~(3+)(M=Sr,Ba)waschangedasCTABconcentrationandpHvaluechanged.TheemissionspectraofMMoO_4:Eu~(3+)(M=Sr,Ba)couldbeadjustedbyCTABconcentrationandpHvalueduetotheirimpactsonthestructure.ItwasimportantthatthedifferentmorphologiesandphotoluminescentpropertiesofMMoO_4:Eu~(3+)(M=Sr,Ba)couldbeobtainedbythefacilehydrothermalmethodandmodulatedbychangingCTABconcentrationandpHvalue.

  • 标签: 纳米发光材料 铕离子掺杂 水热法 SR 发光特性 合成
  • 简介:Differentrareearth(RE)ionsdopantswereaddedintotheSrAl2SiO7:Eu2+phosphorsinordertoenhancethephosphorescenceproperties,andtheeffectoftheREionsincludingYb3+,Ce3+,Nd3+,Dy3+andTm3+,wascomparativelyinvestigated.ItwasfoundthatNd3+additionimprovedthephosphorescencepropertiesobviouslyamongallthestudiedREions.Therefore,Sr1.96–xAl2SiO7:xEu2+,yNd3+phosphorswerestudiedindetail,andtheoptimumEu2+andNd3+concentrationsweredeterminedwiththeafterglowtimeofabout20min.Thephasestructures,photoluminescence(PL)properties,long-lastingphosphorescence(LLP)properties,afterglowdecaycurvesandthermo-luminescence(TL)fortheselectedphosphorsduringthecorrespondingstudywereinvestigated.AllthephosphorsexhibitedgreenPLemissionandLLPemission.ThereweretwoTLbandslocatedatabout325and380Kforthestudiedsamples,andtherelationshipbetweenREadditionandphosphorescencepropertieswasdiscussed.

  • 标签: 稀土掺杂 光性质 荧光粉 磷光 欧盟 稀土离子
  • 简介:Metalsilver(Ag)wasaddedintoSm0.5Sr0.5CoO3(SSC)bynitratepyrolysismethodtoobtainporouscathodematerial(SSC-Agx)forSOFC.ThecompositephasesinthesematerialsofSSC-AgxwereidentifiedbyX-raydiffraction.ThemicrostructureofanelectrodeonCe0.sSm0.2O1.9intermediatetempera-tureelectrolytebyspraymethod,polarizationcurveandtheimperaturepedancespectraatlowandintermediate(500-800℃)wereinvestigated.Theresultsshowthatthematerialcontaining20%Agexhibitsthebestelectrochemicalproperties,itstotalimpedanceofcathodeisonly1/11ofSSCat600℃,andaquarterofSSCsat750℃.Thecompositetech-niqueofcathodeSm0.5Sr0.5CoO3addedwithAgisanefficientmethodtoimprovethecathodeperformanceofSOFCsoperatingintherangeofintermediatetempera-ture.

  • 标签: 燃料电池 固体氧化物 阴极成分 电化学性质 稀土元素
  • 简介:Sr1.995–1.5xGdxSiO4:0.005Eu2+phosphorserieswithx=0–0.08molfornear-ultravioletwhitelight-emittingdiodes(NUVw-LEDs)weresynthesizedviasolid-statereactionmethod.XRDprofilepatternandrefinementresultsdemonstratedthatdopingGd3+ionsresultedinthephasetransformation(β-Sr2SiO4→α’-Sr2SiO4).Thephotoluminescencespectrumofthesamplewithx=0moldisplayedtwoemissionpeakscenteredat470and525nm.Thetwo-peakspectrabecameone-peakspectrawiththeGd3+concentrationincreasing.Actually,thefittingresultsdemonstratedthattheone-peakspectrawerestillcomposedoftwosingleemissionspectra.ThephotoluminescenceintensitywasimprovedandtheCIEchromaticitycoordinateswereadjustedviadopingGd3+.

  • 标签: 过掺杂 荧光粉 Gd 发光性能 晶体结构 紫外发光二极管
  • 简介:Ca8Mg(SiO4)4Cl2:Eu2+phosphordopedwithSr2+cationforCa2+partially,wassynthesizedbysolid-statereactionathightemperatureunderreducingatmosphere,anditsluminescentpropertieswereinvestigated.TheexperimentalresultsindicatethattheemissionintensityofthephosphorincreasesafterbeingdopedwithafewamountofSr2+ion.Theemissionpeakofthephosphorblueshifttoabout464nmwhenthephosphorisdopedwithlargequantityofSr2+ions.TheexcitationspectrumindicatesthatthephosphorcanbewellexcitedbyUVandbluelightfrom300to460nm,andthephosphorwasfittedwellfortheexcitationbyUVorblue-LED.

  • 标签: CALCIUM MAGNESIUM chlorosilicate Eu2+ emission SPECTRUM
  • 简介:Eu2+andDy3+codoped(Ca,Sr)7(SiO3)6Cl2yellowphosphorsweresuccessfullysynthesizedbyself-fluxmethod.Thestructure,morphologyandphotoluminescencepropertieswereinvestigatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andphotoluminescencespectra.Theas-preparedphosphorshowedabroademissionspectrumcenteredat550nmforEu2+single-dopedphosphor,whilelocatedat548–544nmfortheEu2+,Dy3+codopedsamplesunderexcitationat380nmlight.TheemissionintensitywasgreatlyimprovedwhenDy3+wasdopedintothe(Ca,Sr)7(SiO3)6Cl2:Eu2+system.Thecomposition-optimizedsamplewith3mol.%ofDy3+andconstant10mol.%ofEu2+exhibiteda220%PLenhancementcomparedtothephosphorwith10mol.%Eu2+single-doped.Meanwhile,itwasfoundthatthequantumefficiencyofphosphornamely(Ca,Sr)7(SiO3)6Cl2:3mol.%Dy3+,10mol.%Eu2+couldgetupto24.6%.Thesynthesizedyellow-emitting(Ca,Sr)7(SiO3)6Cl2:Dy3+,Eu2+isapromisingcandidateashigh-efficiencyyellowphosphorforNUV-excitedwhiteLEDs.

  • 标签: 镝掺杂 荧光粉 黄色 扫描电子显微镜
  • 简介:LongafterglowphotoluminescentmaterialsSr2MgSi2O7dopedwithEu2+,Dy3+werepreparedbysol-gelmethod.ThesynthesizedsampleswerecharacterizedbyX-raydiffraction.Theexcitationspectrum,emissionspectrumandlongdecaycurveweremeasuredandanalyzed.XRDpatternindicatesthatphosphoriswithSr2MgSi2O7crystalstructure.Thewiderangeofexcitationwavelengthindicatesthatluminescentmaterialcanbeexcitedbylightfromultravioletraytovisiblelight.Themainpeakofemissionspectrumislocatedat466nm.Sampleexcitedbyvisiblelightcanemitbrightbluelight,andtheafterglowtimelastsmorethan8h.

  • 标签: 发光材料 无机非金属材料 稀土
  • 简介:Aseriesofnovelbluelong-lastingphosphorescencephosphorsSr6Al18Si2O37:Eu2+,RE3+(RE3+=Ho3+,Gd3+,Dy3+andPr3+)werepreparedbytheconventionalhigh-temperaturesolid-statereactioninareductiveatmosphere.TheirpropertiesweresystematicallyinvestigatedutilizingX-raydiffraction(XRD),photoluminescence,phosphorescenceandthermoluminescence(TL)spectra.ThephosphorsemittedbluelightthatwasrelatedtotheemissionofEu2+dueto5d-4ftransition.Brightbluelong-lastingphosphorescence(LLP)couldbeobservedaftertheexcitationsourcewasswitchedoff.Fortheoptimizedsample,thebluelong-lastingphosphorescencecouldlastfornearly4hinthelightperceptionofthedark-adaptedhumaneye(0.32mcd/m2).TheeffectsofRE3+ionsonphosphorescencepropertiesofthephosphorswerestudied,andtheresultsshowedthattheco-dopingofRE3+ionsgreatlyenhancedtheintensityofthepeakaround315Kwhichwasrelatedtothelonglastingphosphorescenceofthephosphorsatroomtemperatureandconsequentlyimprovedtheperformanceofthebluephosphorescencesuchasintensityandpersistenttime.

  • 标签: 荧光粉 长余辉 磷光 蓝色 发光特性 高温固相反应