简介:Thesynthesis,compositionoptimization,VUVPhotoluminescence(PL)spectra,andopticalproperties,of(Y,Gd)(V,P)O4∶Eu3+phosphorswereinvestigatedbysynchrotronradiation.TheVUVPLEspectraandthecorrelationamongVUVPLintensity,λem,andEu3+,Gd3+,andP-contentwereestablished.ThePLEspectralstudiesshowedthat(Y,Gd)(V,P)O4∶Eu3+exhibitedsignificantabsorptionintheVUVrange.TheVUVPLintensitywasfoundtoenhancewithPO43-andGd3+-doping.Furthermore,thechromaticitycharacteristicsof(Y,Gd)(V,P)O4∶Eu3+werealsofoundtobe(0.6614,0.3286)andcomparedagainst(Y,Gd)BO3∶Eu3+asareference.Basedonthecharacterizationresults,wearecurrentlyimprovingandevaluatingthepotentialapplicationof(Y,Gd)(V,P)O4∶Eu3+asanewred-emittingPDPphosphor.
简介:ThechemicalstateofgrainboundarycosegregationofCeandPinFe-P-CealloysystemwasstudiedbymeansofAugerElectronSpectroscopy(AES).TheAugerpeaksofCesegregatedatgrainboundariesarefoundwithintherangeof60~180eV.BycomparingwiththeAugerspectraoftheFe-Ce-Pintermetalliccompound,itissupposedthatthereisatwo-dimensionalinterfacialphaseatgrainboundarieswithCeandPcosegregationwhichissimilartothestructureoftheFe-Ce-Pcompound.
简介:ThesinglecrystalgrowthofstoichiometrichostluminescentcrystalNa5Eu(WO4)4hasbeeninvestigated.UsingNa2WO4asaflux,theoptimumconditionstogrowapuresinglecrystalbyflux-slow-coolingmethodhavebeendetermined.Ahighopticalqualitysinglecrystalofdimention4.5mmhasbeengrown,whichisthelargestoneasweknowsofar.Themicro-hardnessofNa5Eu(WO4)4singlecrystalis3.46×103MPa.Itsrefractiveindexis1.81inwhitelightwavelengthregionandthespecificgravityis5.65g/cm3.Thefluorescentandexcitationspectrahavebeendeterminedandthereasonofthefluorescentquenchof5D2and5D1to7FjofEu3+canbeexplainedasmulti-phononnon-radiationtransition.
简介:Cr2O3-formingferriticstainlesssteelshavebeenwidelyexploredasintermediatetemperaturesolidoxidefuelcells(SOFCs)interconnects.However,theevaporationofchromiascalemightmigratetoandpoisonthecathode,leadingtodegradationofthecellperformance.Inthisstudy,Ni-Co-Fe-Pcoatingsweredepositedontheferriticstainlesssteelbymeansofacost-effectivetechniqueofelectrolessmethod.Theyareexpectedtobeconvertedinto(Ni,Co,Fe)3O4spinelwithahighelectricalconductivityandCTEmatchwithstainlesssteel,whichcanblocktheevaporationofchromiaformedonsteelsubstrateexposedtothecathodeenvironmentoftheSOFC.TheeffectsofpH,massratioofFeSO4/(FeSO4+NiSO4+CoSO4)andtemperatureofsolutiononthedepositionrate,compositions,surfacemorphologiesandstructuresoftheNi-Co-Fe-Pcoatingswereinvestigated.TheresultsindicatedthatthedepositionrateincreasedwithincreasingpHwhenpHwaslowerthan9andthenreducedwhenpHwashigherthan9.Thedepositionrateincreasedwithincreasingtemperaturewhentemperaturewaslowerthan80℃andthendecreasedwhentemperaturewashigherthan80℃.ThedepositionratedecreasedwiththeincreaseinmassratioofFeSO4/(NiSO4+CoSO4+FeSO4).ThecoatingsconsistedofNi,Co,FeandP.Thephasestructureofthecoatingwasamorphous.
简介:ThephotoluminescencepropertiesofBiTaO4∶Pr3+andBiTaO4atroomtemperaturewerestudied,andtheinfraredtransmissionanddiffusionreflectionspectraofBiTaO4weremeasured.ThephotoluminescencespectrumofBiTaO4peaksatabout420,440and465nm.Therehasanobviousexcitationbandfrom330to370nm.ThephotoluminescencespectrumofBiTaO4∶Pr3+consistsofthecharacteristicemissionofPr3+,anditsmainpeakisat606nmfrom3P0→3H6transitionofPr3+.Itsexcitationspectrumconsistsofthewidebandwithmaximumat325nm,thewidebandintherangeof375~430nm,andthecharacteristicexcitationofPr3+.Thebandsat325nmand375~430nmmaybefromtheabsorptionofthechargetransfertransitionofthetantalategroupanddefectenergylevelsinitsforbiddenband,respectively.ThereisenergytransferfromhosttoPr3+.BecauseboththehostdensityandphotoluminescencepeakintensityofBiTaO4∶Pr3+aresuperiortoPbWO4,BiTaO4∶Pr3+maybeapotentialheavyscintillator.
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简介:Ca8Mg(SiO4)4Cl2:Eu2+phosphordopedwithSr2+cationforCa2+partially,wassynthesizedbysolid-statereactionathightemperatureunderreducingatmosphere,anditsluminescentpropertieswereinvestigated.TheexperimentalresultsindicatethattheemissionintensityofthephosphorincreasesafterbeingdopedwithafewamountofSr2+ion.Theemissionpeakofthephosphorblueshifttoabout464nmwhenthephosphorisdopedwithlargequantityofSr2+ions.TheexcitationspectrumindicatesthatthephosphorcanbewellexcitedbyUVandbluelightfrom300to460nm,andthephosphorwasfittedwellfortheexcitationbyUVorblue-LED.
简介:Trivalentdysprosium(Dy3+)activatednanocrystallineyttriumvanadate(YVO4)phosphorwassynthesizedviaco-precipitationmethod.ThepreparedsampleswerecharacterizedbyX-raydiffraction(XRD),Fouriertransforminfraredspectroscopy(FTIR),scanningelectronmicroscopy(SEM),opticalabsorptionandphotoluminescence(PL)techniques.TheXRDpatternsrevealthetetragonalcrystallinephase.SEMimagesrevealthatDydopedYVO4nanocrystalsareagglomerated.EDAXconfirmstheformationofYVO4:Dy.FTIRspectrumshowstwostrongabsorptionbandsat459and761cm-1.Opticalabsorptionspectrumshowedthesurfacedefectsintheas-preparedsamples.ThePLemissionspectrumshowstwocharacteristicemissionbandsat485and575nm.Thestrongyellowemissionpeakat575nmisassignedto4F9/2→6H13/2hypersensitivetransitionofDy3+ions,StudyofCIEchromaticitydiagramindicatesthesuitabilityofthephosphorforthedevelopmentofyellow-greenLEDs.