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简介:Layeredcathodematerialsofhigh-temperaturelithiumbatteries,LiNi1/3Mn1/3Co1/3O2aresynthesizedbyasol-gelmethodwithvariationinfinalsinteringtemperatureforboreholeapplications.Thestructure,morphologyandhigh-temperaturedischargeperformanceoftheseresultingproductsareinvestigatedbyX-RayDiffraction(XRD),scanningelectronmicroscopy(SEM),laserparticlesizeanalysis,galvanostaticandpulsedischarge.Theresultsofstructuralanalysisindicatethatthesamplesinteredat800℃hasthecharacteristicsofgoodcrystallinity,narrowsizedistributionandlargespecificsurfaceareaatthesametime.Thedischargeexperimentsalsoindicatethatthissamplehasthebestelectrochemicalproperties,withthemaximumdischargecapacitiesof314.57and434.14mAh·g-1at200and300℃respectivelyandtheminimumcellinternalresistancesatbothtemperatures.
简介:ThetransportpropertiesintheLa2/3(Ca1-xSrx)1/3MnO3(x=0,1/3,2/3)filmspreparedusingtheRFmagnetronsputteringmethodwereinvestigated.TheeffectoftheCa,Srdouble-dopingattheApositionintheLa2/3A1/3MnO3onthestructureofthetargetsandtransportofthefilmshasbeenstudied.Withtheincreaseofx,thestructuresofthetargetstransformfromtherhombohedralphasetothecubicphase;themetal-insulatorphasetransitiontemperature(Tp)ofthefilmsincreases;andthecorrespondingpeakresistivitydecreases.Allthephenomenacanbequalitativelyexplainedbythelatticeeffect.
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简介:Nd_2Zr_2O_7isbeingexploredasanalternatethermalbarriercoating(TBC)materialforoperatingabove1300°C,andgreatefforthasbeenmadetoenlargeitsthermalexpansioncoefficient(TEC)andimproveitstoughness.Inthisstudy,Sc_2O_3wasdopedtoNd_2Zr_2O_7.Thephasestructure,TECsandtoughnessof((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075,0.1)compoundswereinvestigated.((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075)exhibitedpyrochlorestructure,while((Nd_(0.9)Sc_(0.1)))_2Zr_2O_7consistedofpyrochloreandfluoritephases.WiththeincreaseoftheSc_2O_3content,theorderingdegreeofthepyrochloreinthecompoundsdecreased.In((Nd_(1-x)Scx))_2Zr_2O_7series,((Nd_(0.925)Sc_(0.075)))_2Zr_2O_7exhibitedthelargestTEC,whilethetoughnessofthecompoundsincreasedwithincreasingtheSc_2O_3content.Therelatedmechanismswerediscussedbasedonthecrystalstructureanalysis.ConsideringtheTECandtoughness,10mol%Sc_2O_3wassuggestedastheoptimaldopingcontentforNd_2Zr_2O_7ceramic.
简介:通过溶胶凝胶-熔盐法以NaCl为熔盐制备了掺杂Co^2+的Cd1-xCoxFe2O4(x=0~0.5)尖晶石型铁氧体。利用XRD、SEM和VSM等手段对样品进行了结构、形貌和磁性表征,并详细讨论了Co^2+对Co1-xCdxFe2O4(x=0-0.5)铁氧体结构和磁性的影响。结果表明:在研究范围内掺杂后仍然能得到单相尖晶石结构铁氧体;样品均为正八面体;比饱和磁化强度随x的增大而增加。
简介:Inthiswork,hotisostaticpressing(HIPing)techniquewasusedtodensifytheTi_2AlNbpre-alloyedpowder.TheinfluenceofHIPingloadingrouteparameters(temperatureandratesofheatingandpressurizing)onmicrostructureandpropertiesofPMTi_2AlNballoyswasstudied.TheresultsshowedthatHIPingloadingrouteparametersaffectedthedensificationprocessandmechanicalproperties(especiallyhightemperaturerupturelifetime)ofPMTi_2AlNballoysinthepresentwork.Afiniteelementmethod(FEM)modelforpredictingthefinaldensificationwasdevelopedandwasusedtooptimizetheHIPingprocedure.
简介:AseriesofCd1-xZnxS/K2La2Ti3O10compositesweresynthesizedviaasimpleco-precipitationmethod.ThepreparedsampleswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),X-rayenergydispersivespectroscopy(EDX),ultraviolet-visiblediffusereflection(UV-Vis),X-rayphotoelectronspectroscopy(XPS)andphotoluminescence(PL)measurements.ThecompositestructuresconsistedofCd1-xZnxSnanoparticlesevenlydistributedonthesurfaceofK2La2Ti3O10.TheabsorptionedgeofK2La2Ti3O10shiftedtothevisiblelightregionuponintroductionoftheCd1-xZnxSnanoparticles.Thephotocatalyticactivitiesofthecatalystswereevaluatedbyhydrogenproductionundervisiblelightirradiation.ThepreparedCd0.8Zn0.2S(30wt%)/K2La2Ti3O10exhibitedhigherphotocatalyticactivity,evolving6.92mmol/gH2undervisiblelightirradiationfor3h.ThepromotedphotocatalyticactivityofthecompositeswasattributedtothesynergisticeffectbetweenCd1-xZnxSandK2La2Ti3O10,whichresultedinenhancedseparationofphotogeneratedelectronsandholes.
简介:Throughmeasuringthecoefficientoflinearexpansion,thestructureandpropertiesoftheLi2O-Al2O3-SiO2lowexpansionglassceramicscontainingB2O3arestudiedbyJRandXRD.ItisshoutnthattheIRmethodisefficientinthestudyoftheglass-ceramicsstructure.Thereisa"Boronabnormality"inthesystemwhichhasanimportantinfluenceonthepropertiesoftheglass-ceramics.