IMAGING THE INTERNAL ATOMIC STRUCTURE OF LAYER SILICATES. USING THE ATOMIC FORCE .... for studying the internal atomic strucfure of minerals.
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THE CANADIAN |nINER.ALOOIST OFCANADA ASSOCIATION OFTHEMINERATOGIGAT JOURNAL Volume31
September1993
Paft 3
The Cana.dianMineralo gist Vol. 31,pp.541-5s0(1993)
OF LAYERSILICATES IMAGINGTHEINTERNALATOMICSTRUCTURE USINGTHEATOMICFORCEMICROSCOPE FRED J. WICKS Parlt Toronto,ontarioMsS2C6 DeparmentofMineralogy,RoyalontarioMweum,100Queen's KEVIN KJOLLER Barbara'califurnia93117'U.S.A. DiSitallnstrunznts,Inc., 6780CortornDrtve,sa,nta RAY K. EBY{' RoyalontarioMusewt"100Qwen'sParlt Toronto'ontarioM5S2C6 of MineraLogy, Departmznt FRANKC. HAWTHORNE universityof Manitobawinnipeg,ManitobaR3T2N2 sciences, of GeologiidT Department GRANT S. HENDERSONANDGORDONA. VRDOLIAK OntarioMSS3BI Toronto, Street, Russell of Toronto,22 of Geology,.University Departutent ABSTRACI A high tracking force on the Use of the atomic force microscope(AFM) neednot be restrictedto the uppermostsurface. material'snear-surfaceinterreveal a surface-pfe13a{1\s cantilevertip canbe usedto lemove atomsthaicomprisetle upper Forces.of.up.to325 nN on the nal structure.This techniquewas usedto study the 1:1 layer siicate tizarot6, Mg3Si2O(OQa. reveal the hydroxyl groupsand cantilevertip rapidly r"rnou" both th" o*yg"n uod silicon atomsofthe sheetofGtrahedra to of the 1:l layer structure' octahedra and tetrahedra of the sheets both plane to cimmon o*yg"o uto.. that iorm a central The large hexagonalrings of the Similar results were obtained*itn t*o other layered silicates,muscoviteand clinochlore. opelylg for the initiation of the sheetsof tetrahedraappearto be a key factor in the layer-by-layerremoval-bypt:.tj|ing an oH- and satisfy the process.The large rings also allow accessof ambientifrO -otfu"rcs, which iould dissociateto H+ and atoms. surface bondsbrokenby the removalof the g oups,sheetof octahedra' Keywords:lizardite, clinochlore,muscovite,atomic force microscope,atomic resolution,hydroxyl structure. internal structure' surface tetrahedra. sheetof
*hesent address:TopoMetrix, I RobertsonDrive, Bedminster,New Jersey07921-1716'U'S'A'
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TI{E CANADIAN MINERALOGIST
Somuanr k microscopei force atomiquene.,sertpas uniquementd 6tudier la surfaceexterne d"un matdriau.Avec une force de gravureplus forte sur I'aiguitle en cantilever,il,est possibledg.{6glacer les-atomesqui constituentla couchesup6rieurepour ainsi r6v6ler la structureinterne d'un mat6riau,Noris avonsutilis6 cettetecbniquep6ur 6tudier la lizardite, pnyfiosititate t:t llant t9 composition id6ale.Mgrsi,.or(olr)n. une force atteignant 325 nN sir l'^aiguille peut 6roder i la fois les aromes d'oxygbneet de silicium 6u leuitiet de tdhabdres,pour rdvdlerl-esgroupeshydroxyl"r""t t", uto.o o'oxygenequi iorment te plan centralen communavecles feuillets de t6nabdreset d'octaBdres de ta structuie 1:1.Nous avonsobtenudesr6sultatssemblablespour deux autressilicatesen feuillets, muscoviteet clinochlore.Les anneaux hexagonauxdes feuillets de t6traddres semblentatre le facteur cl6 rlansI'abilit6 de d6placerles atomescouchepar couche, en offiot one oou.rt11" fo- tiioiriutioo du processus'ces-anneauxpermetlsntaussil'accds aux mol6culesd'eau'ambiantes,qoi p"o"*t se dissocieren H+ et oH- et ainsi satisfaireles Laisonsrompueslon de l'6limination desatomesde surface. (Traduitpar la R6daction) Mots'cl6s: lizardite, scovite,microscopei force atomique,r6solutionatomique,groupesd,hydroxyle, couche d'octabdres,couchede t6traddres,structurede la surface,structureinterne.
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