简介:Theadsorptionandelectronicpropertiesofisolatedcobaltphthalocyanine(CoPc)moleculeonanultrathinlayerofNaClhavebeeninvestigated.High-resolutionSTMimagesgiveadetailedpictureofthelowestunoccupiedmolecularorbital(LUMO)ofanisolatedCoPc.ItisshownthattheNaClultrathinlayerefficientlydecouplestheinteractionofthemoleculesfromtheunderneathmetalsubstrate,whichmakesitanidealsubstrateforstudyingthepropertiesofsinglemolecules.Moreover,strongdependenceoftheappearanceofthemoleculesonthesamplebiasintheregionofrelativelyhighbias(>3.1V)isascribedtotheimagepotentialstates(IPSs)ofNaCl/Cu(100),whichmayprovideuswithapossiblemethodtofabricatequantumstoragedevices.
简介:Asamemberof1Dnanostructuredmaterials,theferromagneticandnonmagneticmultilayernanowiresexhibittremendouspotentialapplicationsinmanyfieldsduetotheiruniquemagneticandelectricalproperties.Thebasicpropertyofmultilayernanowirearrays,suchascoercivity,iscrucialimportantforthefutureapplication.Inordertoobtainthecoercivityinformation,besidesdirectlymeasuringitthroughexperiment,theoreticalcalculationalsoprovidesausefulandfastwaytoevaluatethemultilayer’scoervicity.Fig.1(a)and(b)demonstrateasinglemultilayernanowireandnanowirearraysembodiedinamatrix,respectively.Inthiswork,byimprovingPant’smodel,wedevelopedthenewmodelandsuccessfullypredictedtherelationshipbetweenthecoercivitychangingofCu/Nimultilayernanowirearraysandstructualparameters.Fig.
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简介:第三的Ni-5%Cu-5%Sn和Ni-10%Cu-10%Sn合金的液体状态undercoolability和水晶生长动力学被玻璃fluxing方法调查。在这二合金,304K的试验性的最大的undercoolings(0.18TL)和286K(0.17TL)被完成,树枝状的生长速度分别地达到39.8和25.1m/s。从进equiaxed结构的粗糙的树突的形态学的转变发生并且谷物尺寸(Ni)当undercooling增加时,显著地分阶段执行减少。格子常数和microhardness与undercooling的改进显然增加。Cu和Sn溶质内容的丰富减少树枝状的生长速度,当时提高格子常数和microhardness(Ni)阶段。
简介:AnefficientprocessfortheconversionofdimethyloxalateintoethyleneglycolwithhighselectivityandhighyieldoverCu2Owasinvestigated.InsituformedCuasatruecatalyticallyactivespeciesshowedagoodcatalyticperformanceforDMOconversiontoproduceEGin95%yield.
简介:StraightandBentnano-cantileverspecimensarerespectivelyproposedtoinvestigatethesingle-modeandmixed-modecrackinitiationattheCu/Siinterfaceedgeinnanoscalecomponents.Withaminuteloadingapparatus,allnanoscalesamplesareinsituloadedandobserved.Numericalanalysisisemployedtoacquirethecriticalinterfacialstressdistributionsduringcrackinitiation.ThestressconcentrationregionsneartheedgeofCu/Siinterfaceinallspecimensarewithinthescaleof100nm,andthecriticalnormalandshearstresseshaveacircularrelationinnanoscalecomponents,whichrepresentsthefracturecriterionoftheinterfaceinnanoscalecomponents.
简介:Inrecentyears,themagneticmultilayerednanomaterialshavebeenextensivelystudiedforelectronics[1],ultrahightensilestrength[2],highstoragemedia[3],andmicrowavedevices[4]sincethegiantmagnetoresistance(GMR)effectwasfoundin1988.Asamemberof1Dnanostructuredmaterials,theferromagneticandnonmagneticmultilayernanowiresalsoexhibittremendouspotentialapplicationsinmanyfieldsduetotheiruniquemagneticandelectricalproperties.Inthiswork,theCu/NimultilayernanowirearraysarepreparediniontracktemplatewithelectrodepositionmethodandanewfacilemethodisfirstintroducedtoeasilyconfirmthedifferentlayerthicknessandcomponentbyremovingthenonmagneticlayerofCu.
简介:Inthiswork,anewphotocatalytsIn(0.1),Cu(x)-ZnS(x=0.01,0.03,0.05)issuccessfullysynthesizedusingsimplehydrothermalmethod.ThephysicalandchemicalpropertiesoftheInandCuco-dopedZnSphotocatalystwerecharacterizedbyX-raydiffraction(XRD),fieldemissionscanningelectronmicroscopy(FESEM),diffusereflectanceUV-visiblespectroscopy(DRUV-visible)andphotoluminescencespectroscopy(PL).Thephotocatalyticactivityoftheas-preparedInandCuco-dopedZnSforhydrogenproductionfromwaterwithNa2SO3andNa2Sassacrificialagentundervisiblelightirradiation(λ≥425nm)wasinvestigated.Thepresenceofco-dopantsfacilitatedtheseparationofelectron-holeaswellasincreasesthevisiblelightabsorption.Theabsorptionedgeoftheco-dopedZnSphotocatalystshiftedtolongerwavelengthastheamountofCuincreases.ThisindicatesthattheabsorptionpropertiesdependedontheamountofCudoped.ThephotocatalyticactivityofsingledopedIn(0.1)-ZnSwassignificantlyenhancedbyco-dopingwithCuundervisiblelightirradiation.ThehighestphotocatalyticactivitywasobservedonIn(0.1),Cu(0.03)-ZnSwiththehydrogenproductionrateof131.32μmol/hundervisiblelightirradiation.Thisisalmost8timeshigherthansingledopedIn(0.1)-ZnS.
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简介:Theglass-formingability(GFA)andmagneticpropertiesoftheGd_(50)Coso-basedamorphousaiioywithAladditionsubstitutionforCoareinvestigated.ItisfoundthattheGFAandmagneto-caloriceffectoftheGd_(50)Co_(45)Al_5amorphousaiioyarebetterthanGd_(50)Co_(50)amorphousalloy.Themaximummagneticentropychange(-△S_m~(peak))andthemagneticrefrigerantcapacityoftheamorphousalloyunderafieldof5Tareabout6.64J·kg~(-1)K~(-1)and764J·kg~(-1),respectively.Thefielddependenceofmagneticentropychangemeetstheonepredictedbythemeanfieldtheory,whichisinvestigatedforabetterunderstandingofthemagneto-caloricbehaviorsoftheGd_(50)Co_(45)Al_5amorphousalloy.
简介:ThisarticleaddressesthesynthesisoforganicallytailoredNi-Allayereddoublehydroxide(ONi-AlLDH)anditsuseinthefabricationofexfoliatedpoly(methylmethacrylate)(PMMA)nanocomposites.ThepristineNi-AlLDHwasinitiallysynthesizedbyco-precipitationmethodandsubsequentlymodifiedusingsodiumdodecylsulfatetoobtainONi-AlLDH.NanocompositesofPMMAcontainingvariousamountsofmodifiedNi-AlLDH(3wt%?7wt%)weresynthesizedviasolventblendingmethodtoinvestigatetheinfluenceofLDHcontentonthepropertiesofPMMAmatrix.SeveralcharacterizationmethodssuchasX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),Fouriertransforminfraredspectroscopy(FTIR),rheologicalanalysis,differentialscanningcalorimetry(DSC)andthermogravimetricanalysis(TGA),wereemployedtoexaminethestructural,viscoelasticandthermalpropertiesofPMMA/OLDHnanocomposites.TheresultsofXRDandTEMexaminationconfirmtheformationofpartiallyexfoliatedPMMA/OLDHnanocomposites.TheFTIRresultselucidatethatthecharacteristicbandsforbothpurePMMAandmodifiedLDHarepresentinthespectraofPMMA/OLDHnanocomposites.Rheologicalanalyseswerecarriedouttoexaminetheadhesionbetweenpolymermatrixandfillerspresentinthenanocompositesample.TheTGAdataindicatethatthePMMAnanocompositesexhibithigherthermalstabilitywhencomparedtopurePMMA.ThethermaldecompositiontemperatureofPMMA/OLDHnanocompositesincreasesby28KcomparedtothatofpurePMMAat15%weightlossasapointofreference.IncomparisonwithpurePMMA,thePMMAnanocompositecontaining7wt%LDHdemonstratesimprovedglasstransitiontemperature(Tg)ofaround3K.Theactivationenergy(Ea),reactionorders(n)andreactionmechanismofthermaldegradationofPMMA/OLDHnanocompositeswereevaluatedusingdifferentkineticmodels.WateruptakecapacityofthePMMA/OLDHnanocompositesislessthanthatofthepurePMMA.
简介:AnewlayeredCu-basedoxychalcogenideBa3Fe2O5Cu2S2hasbeensynthesizedanditsmagneticandelectronicpropertieswererevealed.Ba3Fe2O5Cu2S2isbuiltupbyalternativelystacking[Cu2S2]2-layersandironperovskiteoxide[(FeO2)(BaO)(FeO2)]2-layersalongthecaxisthatareseparatedbybariumionswithFe3+fivefoldcoordinatedbyasquare-pyramidalarrangementofoxygen.Fromthebondvalencearguments,weinferredthatinlayeredCuCh-based(Ch=S,Se,Te)compoundsthe+3cationinperovskiteoxidesheetprefersasquarepyramidalsite,whilethelowervalencecationprefersthesquareplanarsites.Thestudiesonsusceptibility,transport,andopticalreflectivityindicatethatBa3Fe2O5Cu2S2isanantiferromagneticsemiconductorwithaNe′eltemperatureof121Kandanopticalbandgapof1.03eV.Themeasurementofheatcapacityfrom10Ktoroomtemperatureshowsnoanomalyat121K.TheDebyetemperatureisdeterminedtobe113K.TheoreticalcalculationsindicatethattheconductionbandminimumispredominantlycontributedbyO2pand3dstatesofFeionsthatantiferromagneticallyarrangedinFeO2layers.TheFe3dstatesarelocatedatlowerenergyandresultinanarrowbandgapincomparisonwiththatoftheisostructuralSr3Sc2O5Cu2S2.
简介:基于刚性配体2-(4-噻唑基)苯并咪唑和二价金属铜离子在水热条件下成功地合成了2个Keggin型多酸化合物[CuⅡ(L1)2(H2O)]2[SiW12O40](1)和[(L1)4(L2)2(H3PMo12O40)2]·5H2O(2)(L1=2-(4-噻唑基)苯并咪唑,L2=苯并咪唑).通过单晶X-射线、红外光谱和元素分析对化合物1和2进行了表征.在化合物1中,存在2个独立的结构单元:Keggin型多酸和蝴蝶状的络合物阳离子[Cu(L1)2(H2O)]2+.化合物2为含有混合配体的超分子结构,由Keggin型多酸、4个游离的L1和2个L2配体组成.此外,研究了化合物1和2的电化学和光催化性能.
简介:High-performancethin-filmtransistors(TFTs)withalowthermalbudgetarehighlydesiredforflexibleelectronicapplications.Inthiswork,theTFTswithatomiclayerdepositedZnO-channel/Al_2O_3-dielectricarefabricatedunderthemaximumprocesstemperatureof200℃.First,weinvestigatetheeffectofpost-annealingenvironmentsuchasN_2,H_2-N_2(4%)andO_2onthedeviceperformance,revealingthatO_2annealingcangreatlyenhancethedeviceperformance.Further,wecomparetheinfluencesofannealingtemperatureandtimeonthedeviceperformance.Itisfoundthatlongannealingat200℃isequivalenttoandevenoutperformsshortannealingat300℃.ExcellentelectricalcharacteristicsoftheTFTsaredemonstratedafterO_2annealingat200℃for35min,includingalowoff-currentof2.3×10~(-13)A,asmallsub-thresholdswingof245mV/dec,alargeon/offcurrentratioof7.6×10~8,andahighelectroneffectivemobilityof22.1cm~2/V·s.Undernegativegatebiasstressat—10V,theabovedevicesshowbetterelectricalstabilitiesthanthosepost-annealedat300℃.Thusthefabricatedhigh-performanceZnOTFTwithalowthermalbudgetisverypromisingforflexibleelectronicapplications.