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ID:42564289
大小:1.24 MB
页数:4页
时间:2019-09-17
《XRD简介(英文)》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、OpticalrelatedtechnologyX-rayDiffractionAbstract:X-raydiffraction(XRD)technologyiswidelyusedinmaterialscharacterization.Identifychemistryconstituentsoftheproduct,analyzethespacegroup,latticeparameterandetc.Inthisarticle,IwillintroducetheprincipleofXRDincludingthediffracto
2、meterandsimpleapplicationwiththeXRDpattern.Introduction1.X-rayisakindofelectromagneticradiationgeneratedbytheinnerelectrontransition.Itswavelengthrangingfrom0.01to10nm.X-rayphotonswithashortwavelength(below0.2nm)havetheenergiesabove5keV.Thereforecomesthepenetratingability
3、[1].Moreover,X-rayinteractwithmatterandprojectthematter’sinformationinX-raydiffractionpattern.Asresult,X-rayarewidelyusedtoimagetheinsideoftheobjectandisthoughthighlyinthefieldmedicalradiographyandmaterialcharacterization.2.X-raydiffractionisaninteractionbetweenX-rayandma
4、tter.Considerthematerialaslatticeasshowatfigure1.Considerthesituationaswhatwehadlearned-theRayleighscattering.Insomedirection,wecandetecttheinterferenceoftwonarrowX-raybeams,andconstructiveinterferencemeettheopticalpathdifference:2dsinθ=nλ(n=0,1,2…).KwonastheBragg’slaw.di
5、sthedistancebetweentwoparticles,θistheanglebetweenincidentX-rayandlatticeplane,λisthewavelengthofX-ray.Wecanlearnfromtheequationthattheconstructiveinteronlyhappeninsomeparticularanglesincethewavelengthandthedistance(considerasthegratingconstant)arefixedforonematerial,andf
6、orthethreedimensionalworldwehavethreeconstantmarkedas(hkl)todescribethespacegroup.Nevertheless,ishardtodirectlydetectthe3Dpattern,instead,weintroducethesphericalprojectionpatternanddevelopsomemathematicaltranslationtorestructurethe3Dconditionshowsatfigure2.Wecanlearnthedi
7、rectionanddistancefromthesphericalcoordinate.Let’sgoovertheprocedureofXRD.FirstweshotaX-raytothesampleandgetitsdiffractionpatternandreadtheinformationfromthe2Dpattern[2].3.X-rayDiffractometerishighintegrationopticalapparatusshowsatfigure3.TheX-raysourceusuallychoosesCuast
8、argetmaterialapplyinghotelectronswhichacceleratedbyhighvoltageandgenerateX-ray[3].Sampleplatform
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