文稿案例讲稿x ray diffraction

X-RayDiffractionX-raydiffraction(XRD)isaversatile,non-destructivetechniquethatrevealsthedetailedinformationaboutthechemicalcompositionandcrystallographicstructureofnaturalandmanufacturedmaterials.0 2-theta

Phase ThediffractionpatternforeveryphaseisasuniqueasyourfingerprintPhaseswiththesamechemicalcompositioncandrasticallydifferentdiffraction UsethepositionandrelativeintensityofaseriesofpeakstomatchexperimentaldatatothereferencepatternsintheSilica：glass,quartz,

tativePhase Withhighqualitydata,youcandeterminehowmuchofeachphaseispresent–mustmeettheconstantTheratioofpeakvarieslinearlyasafunction

II(phasea)/I(phaseb) ..0

weightfractionsforanyphasesina–needtoknowtheconstantof

RIRmethodisfastandgivestativeWholepatternfitting/Rietveldrefinementisamoreaccuratebutmore UnitCellLatticeParameterRefinement Byaccura ymeasuringpeakpositionsoveralongrangeof2theta,youcandeterminetheunitcelllatticeparametersofthephasesinyoursamplealloying,substitutional ,temperatureandpressure,cancreatechangesinlatticeparametersthatyoumaywantusemanypeaksoveralongrangeof2thetasothatyoucanidentifyandcorrectforsystematicerrorssuchasspecimen cementandzeroshiftmeasurepeakpositionswithapeaksearchalgorithmorprofilefittingismoreaccuratebutmoretimethennumericallyrefinethelatticeCrystalliteSizeand Crystallitessmallerthan~120nmcreatebroadeningofthispeakbroadeningcanbeused fythecrystallitesizeofnanoparticlesusingtheScherrermustknowthecontributionofpeakwidthfromtheinstrumentbyusingacalibrationcurvemicrostrainmayalsocreatepeakIntensity yzingthepeakwidthsoveralongrangeof2thetausinga043>lerinite-COIntensitycrystallite L2PreferredOrientation Preferredorientationofcrystallitescancreateasystematicvariationindiffractionpeakintensitiescan yzeusinga1Ddiffractionapolefiguremapstheintensityofasinglepeakasafunctionoftiltandrotationofthesamplethiscanbeused fythe

00-004-0784>Gold-86

422

Two-ThetaBasisof 晶体学基础Characteristicsofcrystals－Homogeneous－均匀性Anisotropy－各向异性:电导率、热膨胀系数、折光率等Conductivity,Coefficientofthermalexpansion,RefractiveindexDeterminatemeltingpointSymmetryDiffractiontocrystals－晶体对X- 定律的现象Single-slit Circularaperture包括：单缝衍射、圆孔衍射、圆板衍射及 光在过程中，遇到

衍射时产生的明暗条纹或光环，叫衍射图样衍射波所共有的行为。日常生活中声波的圆屏、狭缝、细丝、刀口、直边等物时，在足够CrystallatticeAcrystallatticeisaregularthree-dimensionaldistribution(cubic,rhombic,etc.)ofatomsinspace.Thesearearrangedsothattheyformaseriesof nesseparatedfromoneanotherbyadistanced,whichvariesaccordingtothenatureofthematerial.Foranycrystal, nesexistinanumberofdifferentorientations-eachwithitsownspecificd- TheunitcellisthebasicrepeatingunitthatdefinesasamesymmetrywithMacroscopiccrystals;(2)rightAngle;(3)smallest晶胞参数(Unitcellparametrs):包括晶胞中三个基本向量(basicvector，a、b、c)及三个方向的夹角（angle，α、β、γ）。

β βaxzzy（a,0,（0,b,xfaceandcrystal（Miller数(h,k,l)来表示。TwoMillerindexincubicTheingelectronmusthaveenoughenergytoremoveinner1selectronsfromthecopperatoms.ThisenergycorrespondstotheCuabsorptionedgeThe2sand2pelectronsfallbackintothe1ssandemittheK1K2lines.

MLK

MLK BasesBasesofcrystalsdiffractedbyX-Diffractionoccursaswavesctwithastructurewhoserepeatdistanceisaboutthesameasthewavelength.Thephenomenoniscommoninthenaturalworld,andoccursacrossabroadrangeofscales.Forexample,lightcanbediffractedbyagratinghavingscribedlinesspacedontheorderofafewthousandangstroms,aboutthewavelengthoflight.XXXX线的“反射”，这种特定条件的反射就是晶面对X射线的衍射。ItIthappensthatX-rayshavewavelengthsontheorderafewangstroms,thesameastypicaldistancesincrystallinesolids.ThatmeansX-rayscanbediffractedfrommineralswhich,bydefinition,arecrystallineandhaveregularlyrepeatingatomicWhencertaingeometricrequirementsaremet,X-raysscatteredfromacrystallinesolidcanconstructivelyinterfere,producingadiffractedbeam.In1912,W.L.Braggrecognizedapredicatablerelationshipamongseveralfactors.散射波长与入射波相同BraggθodAtomsseparatedbydistancedwillscatterinphasewhenthepathlengthdifferenceθodPathlengthdifferenceAB+BC=nλ=2dsin

d-BDerivationtheBApplicationofXRDin0 2-theta

PhasePhase UnitCrystalliteXRDpatternsofthreesamplescontaining5%Fe(III)sinteredat873Kfor2h.pH1.8;(b)pH3.6;and(c)pHCexZr1-xO2solid

:CobaltPDF_Number:[42- :Co3Wavelength:1.540598252531262075334622244417113642973138002660675126622840

Peaklist[Range1 111 220 111 220 3119222Spacegroup: 400 :8 422 OOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDemOriginDem OriginDemOriginDemOriginDemOriginDemOriginDemOriginDem

2

:CeriumPDF_Number:[81- :CeWavelength:1.540598 :CubicSpacegroup:Fm-3m :5.4124Peaklist[Range1!

111200220311 222 400 3 420 4

2

Example1:Solidbase--Self-condensationofSelf-condensationofExample2:Solidacid--Al-containingmesoporousNH3-AcetalationofcyclohexanonewithNH3-NH3-TPDofAl-SBA-15withdifferentSi/AlCarbon-basedSolidAcid-Fructoseto Table1ConversionandselectivityinfructoseSelectivityReactioncondition:0.4gcatalyst,0.5gfructose,6mLsolvent,130 C,1.5hours.Table2Thestructureandsurfacepropertiesofthecatalystsandcorrespondingcatalyticperformancesa

HMFHMFYeild

SynergisticWith-COOHH--aReactioncondition:0.4gcatalyst,0.5gfructose,6mLDMSO,oC,