电子能量损失谱eels

½0½3/213/25/22½0½3/215/27/23/25/2½3/2½½j03210l4s24p24p44s24d44d64f64f832N3s23p23p42s23d43d618M2s22p22p48L1s22KM5M4M3(n-3)M2M1L3(2p3/2)L2(2p1/2)(n-2)L1(2s)K(n=1,1s)Kα1Kα2Kβ1Lα1:(STEM)(,,EDX,EELS):------XX1X,(Z11),2%,1%21,2~1eV,mapping3,,Elasticscattering(Diffraction)Xrays(EDXS)AugerelectronsBackscatteredelectronsInelasticscattering(EELS)SecondaryelectronsSpecimenProbeelectrons:Z1:EB=BindingenergyofelectroninsampleE0-∆E∆E-|EB|AtomicviewofsampleProbeelectron(Energy=E0)HitachiHD2000STEMEELS————plasmaEELSA12550eVP(1)/P(0)=t/Lp(P(1)P(0)tLp350eVedge——,——BELNES50eVEnergy-loss[eV]01005006007008009001000IntensityOxygenedgeNickeledgeZero-lossLow-lossHigh-lossPlasmonx1000(Valenceelectrons)ELNESElementalcompositionBondingCoordinationDielectricfunctionThicknessInterat.dist.EXELFS(Coreelectrons)BondingcEXELFS50-300eV——1Gatan,omega1parallelserial22EELSserial0.1eV/channel—10eV/channelparallel:SEELSPEELSPEELSSEELS3EDXZ11X2XEDX1EELS20%-50%EDXEDXIEELS——1nm1nA12II110-18—10-12W100keV2.5eVLaB6100keV1eV10-210.35-0.5eV0.3%-5%LaB6100keV1eV21.53slitSEELS)PEELS0.37eV@FWHMZero-LossPeakHD-2000200keV/150pAFieldemissiondistribution41EELS25GatanImagingFilterEELSm0v121——ε0n10mrad100nmt=λIp/I0(Ip()20EEmθγν≈12221cνγ−⎛⎞=−⎜⎟⎝⎠122022pphhneEmωππε⎛⎞==⎜⎟⎝⎠23120mrad2•EELS––Cu+(Cu2O)Cu2+(CuO)9301030Energy-loss[eV]1130Hofer&Golob,UM21(1987)379520540560580600Energy-loss[eV]MnOFe2O3O2CoONiOOxygenKedge————4SELESPEELSchannel12α34/55nm800mm5mrad1-10mradEELS100mrad67810ms-1s/channelZ13AlK;19-2837-45L;5569MFittedbackgroundExtractededgeintensityLow-lossintensityNX=IX/(IL*σX)NX/NY=IX/IY*σY/σXAbsolutequantRelativequant••cross-sections(σ)••––•––NX=IX/(IL*σX)NXXIXXILσXX)EDXEELSEDX15100eVEELS10%1eVZ1Z2∆x∆y∆E•100pointsacquiredin1min•AcquiredonHD-2000at200keVExample-LineprofilesBasicspectrumimageprocessing•EELSspectrumimage[160,90]pixels,1022energychannels•AcquiredonHD-2000at200keV12EELSEDX1EELS,EDX2:EELS,k;EDX3EELS(Z30),4mapping:EELS,;EELSEELSEDXZZ30EDXEDXEDXEELS100eV0.32eV(~30eV),200keV~100nmZ(Z10)Z•EELS,,mapping,•:––MappingTEMEDSXrayTEMEELS