資源描述：
《1245_Compositional-partition-in-Ag-Nb-alloy-clusters-produced-by-a-plasma-gas-condensation-cluster-source》由會員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、NanoStructuredMaterials,Vol.11,No.8,pp.1245±1251,1999ElsevierScienceLtdPergamonCopyright?2000ActaMetallurgicaInc.PrintedintheUSA.Allrightsreserved.0965-9773/99/$±seefrontmatterPIIS0965-9773(99)00415-8COMPOSITIONALPARTITIONINAg-NbALLOYCLUSTERSPRODUCEDBYAPLASMA-GAS-CONDENSATIO
2、NCLUSTERSOURCEK.Wakoh*,T.Hihata**,D.L.Peng**andK.Sumiyama**InstituteforMaterialsResearch,TohokuUniversity,Sendai980-8577,Japan**CREST,JapanScienceandTechnologyCorporation(JST),Kawaguchi332-0012,Japan(ReceivedSeptember27,1999)(AcceptedNovember5,1999)AbstractDWehaveproducedAg-
3、Nbclustersbyafacing-targettypeplasma-gas-condensationclustersourceasourfirststeptowardalloyclusterformation.TheAg-Nbclustershavebeendepositedonsubstratesandexaminedbyatransmissionelectronmicroscopewithanano-beamenergydispersiveX-rayanalysis.WehaveobtainedAg-Nballoyclusterswi
4、ththesizesrangebetween5and10nmindiameter.TheirchemicalcompositionsarebroadlydispersedandpartitionedintoAg-richandNb-richones,beingconsistentwiththeimmiscibletypeequilibriumphasediagram.Thisresultsuggeststhatalloyclusterformationisdrivenbythealloyphasestability.?2000ActaMetal
5、lurgicaInc.IntroductionAgreatdealofinteresthasbeenconcentratedonnano-scaleheterogeneousmaterialssuchasnano-crystallineandgranularmaterials(1)becausetheirphysicalandchemicalpropertiesaresignificantlydifferentfromhomogeneouscounterparts.Thesematerialshavebeenmainlyobtainedbypr
6、ecipitationofsmallcrystallitesinamatrixvialowtemperatureheattreatmentofsupersaturatedprecursorswhicharepreparedbyvapor-,liquid-,andsolid-quenchingmethods.Smallparticlesandclustershavebeenalsocandidateprecursorstoobtainsuchstructure-controlledmaterialsinnanometerscale(2±4).Si
7、ncetheyhavetheuniquestructuresandpropertiesowingtotheirnanometersizes(4±7),ithasbeendesiredtofabricateparticle-orcluster-assembledmaterials(2,4).Inordertooptimizetheirproperties,weneedsize-selectedclustersasbuildingblocks.Forthefirststep,wehaverecentlyconstructedplasma-gas-c
8、ondensation(PGC)typeclusterdepositionapparatus(7±9),whichissimilartotheoneo
