Local atomic structures of hematite nanoparticles studied with XAFS

(整期优先)网络出版时间:1999-01-11
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Hematitenanoparticleswhichwerecoated,respectively,withsodiumdodecylebenzenesulphonate(DBS)andcetyltrimethylammoniumbromide(CTAB)weresynthesizedbyusingmicroemulsionmethodinthesystemofwater/toluene.Theparticlesizeandshapewerecharacterizedwithtransmissuonelectronmicroscopy(TEM).TheTEMresultsshowthatthenanoparticlestaketheshapeofshperewithdimeterof5.0nmand6.0nmformodifiedDBSandCTABrespectively.ThelocalatomicstructuresofthesenanoparticleswereprobedbyusingXAFStechnique.Fe-Kabsorptionspectrawerecollectedatbeamline4W1BofBSRF.ThelocalatomicstructureinDBScoatedhematitewasfoundtobesimilarwiththatinbulkhematiteexcepttheanharmonicityincreasing,butabout0.04AexpansionofFe-ObondlengthinCTAB-coatedhematite,Theinterface/surfaceatomicconfigurationwerecomparedanddiscussed.