简介:Duetotheremarkablemagnetoresistance(MR)effectonperovskite-typemanganite,magnetoelectronicsandspintronicshavebecomeattractivesubjectsofexperimentalandtheoreticalinvestigationsfortheapplicationpurpose.(La0.9Nd0.1)2/3Ca1/3Mn1-xFexO3(x=0,x=0.05)werepreparedsuccessfullybysol-gelmethod.Thestructure,magneticproperties,andtransportpropertiesofthecompoundswereinvestigated.Themagnetoresistanceeffectdependsonthecompositionandthetemperature.XRDpatternsshowthatthecompoundisasinglephasepolycrystalwithpseudocubicstructure.Alargenegativeisotropicmagnetoresistanceeffectinthesampleswereobservedatlowtemperatureregion.ThemaximumMRofthesampleswas77%and97%,respectively.Itwasmostlikelyduetothescatteringorthetunnelingtransportofspin-polarizedcarriersinlatticeunderstrongmagneticfield.
简介:InordertosensitizetheluminescenceofEu3+ionsinheavymetalglass,zincleadborateglasssamplescontainingvariousconcentrationsofEu3+andTb3+ionswerepreparedtostudytheTb3+toEu3+non-radiativeenergytransferphenomena.EnergylevelstructuresofTb3+andEu3+ionswereplottedtoshowtheexcitationandenergytransferroutes.EfficientenergytransferfromTb3+toEu3+wasobservedandstudiedqualitativelyintermsofdopingconcentrations.Thesensitizationturnedouttobelesseffectivethanexpected.FurtherstudiestocharacterizetheoxidationofTb3+intotetravalentstateandtoexaminethemechanismofenergytransferareproposed.
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简介:Eu3+/Sm3+codopedBiPO4黄磷与没有表面活化剂的环境经由一个灵巧的热水的方法被综合。X光检查衍射分析证明样品拥有了标准BiPO4单斜晶的结构。扫描电子显微镜学图象证明所有样品与像梭的形状分散得好的、测微计大小的晶体创作了。到Eu3+的从Sm3+的精力转移被光系列和Sm3+4G5/26H5/2排放的腐烂过程证实。橘子红光能在Eu3+/Sm3+codopedBiPO4黄磷被获得。Sm3+4G5/26H5/2排放的平均一生在BiPO4:0.03Sm3+在BiPO4:0.03Sm3+从2.70ms减少了到2.37ms,0.05Eu3+。在395nm附近的强壮、宽的吸收乐队,从Eu3+的7F05L6转变和Sm3+的6H5/24K11/2转变发源,资助BiPO4:Eu3+,有近紫外激动的white-light-emitting二极管的域里的潜在的应用程序的Sm3+黄磷。
简介:Cr的Nanopowder:Cr的GGG和nanopowder,Nd:有从0.1at.%到1.5at.%的Cr3+的不同集中的GGG被大音阶的第五音胶化方法用醋酸和乙烯乙二醇综合。热gravimetric分析和微分扫描热量测定(TGA-DSC),X光检查衍射(XRD)和光致发光光谱学被用来描绘粉末。当在1000点对待时,雏晶尺寸是大约58nm?????????????????猯灵?匠?猼'T资???猼灵?????????猯'T??猼灵???? ̄?????猯'T????猯灵??猼'T?????吗????????????????‵渠????????浮??
简介:LanthanidedopedNaYF4microcrystalsweresynthesizedviaafacilehydrothermalmethod.MulticolorupconversionluminescencewasobservedinNaYF4microcrystalsdopedwithYb3+/Er3+,Yb3+/Tm3+,andYb3+/Er3+/Tm3+undertheexcitationof980nminfraredlight.Importantly,theexcitationpowerdensitydependenceofupconversionemissionintensityindicatedclearlytheenergytransferfromTm3+toEr3+ionsundertheexcitationoflowpowerdensity(5×102–9×102W/cm2).Meanwhile,theinverseenergytransferfromEr3+toTm3+ionsundertheexcitationofrelativelyhigherpowerdensity(4.1×104–4.9×104W/cm2)wasalsorevealed.ThiswasadirectevidenceforreversibleenergytransferbetweenEr3+andTm3+ions.Undertheexcitationofhighpowerdensity(4.1×104–4.9×104W/cm2),darksensitizerswerealsomotivatedsothatthebottleneckeffectofhighconcentrationYb3+iondopingwasbroken.ThiswasthemainreasonforrealizinghighupconversionefficiencyofthesampleswithheavydopingofYb3+ion.
简介:Redphosphor(Y,Gd)BO3:Eu3+withgrainshape,smallsize,non-agglomerate,highcrystallinityandgoodphotoluminescence(PL)intensitywaspreparedbyacomplexmethodthattheprecursorofthephosphorwaspreparedbyco-precipitationmethodandthephosphorwaspreparedbycombustionmethod.TheSEMphotosandthephotoluminescencespectrumexcitedunderVUVshowthatthemorphologyandluminescentpropertiesofthisphosphoraresatisfiedwhenanappropriateamountofureawasadoptedasthecombustionagentinthepreparationprocedure.
简介:TheelectrodeprocessofY3+iononmolybdenumandnickelelectrodeshasbeenstudiedbycyclicvoltammetryandchronopotentiometryintheYCl3-NaCl-KClmelt.Theoverallchargetransferprocessisatwo-stepreaction:Y3++e=Y2+;Y2++2e=Y.YttriumreducedonthenickelelectrodecanformaseriesofNi-Yalloys.X-raydiffractionanalysiswasemployedtodeterminethealloycompositionsformedunderdifferentcon-ditions.
简介:简要介绍HotEye热眼技术工作原理,并通过分析H型钢的缺陷位置及相应的形状特征,提出H型钢表面质量自动检测技术的应用可行性和系统设计特点,为型钢表面质量自动检测提供切实可行的理论方案。