Yuav ua li cas cov qauv duab ntawm scanning electron microscopy thiab kis electron microscopy txawv
Kev kuaj xyuas electron microscopy feem ntau suav nrog cov duab hluav taws xob thib ob tom qab electron beam irradiation ntawm tus qauv, thaum lub teeb pom kev zoo ntawm kev xa hluav taws xob microscopy yog kev xa hluav taws xob.
Electron microscope, abbreviated li electron microscope, tau dhau los ua ib yam khoom tseem ceeb thiab tseem ceeb hauv kev tshawb fawb thiab thev naus laus zis niaj hnub tom qab ntau tshaj li tsib caug xyoo ntawm txoj kev loj hlob.
Lub tshuab ntsuas hluav taws xob muaj peb ntu: lub iav raj, lub tshuab nqus tsev, thiab lub txee fais fab.
Lub lens fwj feem ntau muaj cov khoom siv hluav taws xob, cov khoom siv hluav taws xob, cov qauv racks, cov ntxaij vab tshaus fluorescent, thiab cov khoom ntes, uas feem ntau yog sib sau ua ke rau hauv ib kab los ntawm sab saum toj mus rau hauv qab.
Electronic lo ntsiab muag yog siv los tsom electrons thiab yog qhov tseem ceeb tshaj plaws nyob rau hauv lub raj ntawm electron microscope. Cov lo ntsiab muag sib nqus feem ntau yog siv, thiab qee zaus cov lo ntsiab muag electrostatic kuj siv. Nws siv lub spatial hluav taws xob los yog magnetic teb symmetrical rau lub axis ntawm daim iav raj los khoov lub electron trajectory ntawm lub axis, ua kom pom tseeb. Nws txoj haujlwm yog tib yam li lub lens kho qhov muag (convex lens) nyob rau hauv lub tshuab kho qhov muag kom pom lub teeb ntawm lub teeb, yog li nws yog hu ua electron lens. Lub hom phiaj ntawm lub lens kho qhov muag yog tsau, thaum lub teeb pom kev ntawm lub lens electron tuaj yeem hloov kho, yog li lub tshuab ntsuas hluav taws xob tsis muaj lub lens txav tau zoo li lub tshuab ntsuas qhov muag. Niaj hnub nimno electron microscopes feem ntau siv electromagnetic lo ntsiab muag, uas tsom electrons los ntawm ib tug muaj zog magnetic teb generated los ntawm ib tug ruaj khov DC excitation tam sim no dhau los ntawm ib tug coil nrog ncej khau. Cov khoom siv hluav taws xob yog tsim los ntawm cov cathode uas tso tawm cov hluav taws xob dawb, lub rooj vag, thiab cov anode uas ua kom cov hluav taws xob nrawm hauv cov qauv ncig. Qhov sib txawv voltage ntawm cathode thiab anode yuav tsum siab heev, feem ntau ntawm ntau txhiab volts thiab 3 lab volts. Nws tuaj yeem emit thiab tsim cov kab hluav taws xob nrog lub nrawm nrawm, yog li kev ruaj ntseg ntawm qhov nrawm nrawm yuav tsum tsis pub tsawg dua ib txhiab.
Cov qauv tuaj yeem muab tso rau hauv cov qauv khib nyiab, thiab feem ntau cov khoom siv tuaj yeem siv los hloov cov qauv (xws li txav, tig, cua sov, txias, ncab, thiab lwm yam).
Vim li cas thiaj siv lub vijtsam fluorescent? Vim tias lub teeb hluav taws xob tsis tuaj yeem pom los ntawm qhov muag liab qab, nws yuav tsum tau siv lub vijtsam fluorescent tig lub teeb hluav taws xob mus rau qhov pom lub teeb pom kev thiaj li tsim tau cov duab uas tuaj yeem pom ntawm lub qhov muag.
Detectors yog siv los sau cov cim hluav taws xob lossis cov teeb liab thib ob.
Cov kab hluav taws xob hluav taws xob ntawm lub tshuab ntsuas hluav taws xob tsis dhau los ntawm cov qauv, tsuas yog tsom rau cov kab hluav taws xob ntau li ntau tau ntawm thaj tsam me me ntawm cov qauv, thiab tom qab ntawd luam cov qauv kab los ntawm kab. Qhov xwm txheej electrons ua rau cov qauv saum npoo zoo siab nrog cov electrons thib ob. Lub microscope soj ntsuam cov electrons tawg los ntawm txhua qhov chaw. Cov siv lead ua ci ci tso rau ntawm ib sab ntawm cov qauv tau txais cov khoom siv hluav taws xob thib ob, thiab hloov cov hluav taws xob siv hluav taws xob ntawm cov duab raj tom qab kev nthuav dav, yog li hloov qhov ci ntawm daim duab raj fluorescent screen. Cov duab yog ib daim duab peb sab uas qhia txog cov qauv saum npoo ntawm cov qauv. Lub deflection coil ntawm daim duab raj yog synchronized nrog lub electron beam ntawm tus qauv nto rau scanning, yog li ntawd lub fluorescent screen ntawm daim duab raj qhia morphology duab ntawm tus qauv nto, uas yog zoo ib yam li lub hauv paus ntsiab lus ua hauj lwm ntawm industrial TV. Vim lub fact tias electrons nyob rau hauv xws li ib tug microscope tsis tas yuav kis tau los ntawm cov qauv, qhov voltage ntawm electrons ceev tsis tas yuav tsum tau siab heev.
Qhov kev daws teeb meem ntawm scanning electron microscope feem ntau yog nyob ntawm txoj kab uas hla ntawm lub teeb hluav taws xob ntawm qhov chaw ntawm tus qauv. Qhov kev nthuav dav yog qhov piv ntawm qhov ntsuas amplitude ntawm lub raj imaging rau lub scanning amplitude ntawm tus qauv, uas tuaj yeem hloov pauv tsis tu ncua los ntawm kaum tawm zaus mus rau ntau pua txhiab zaus. Scanning electron microscopy tsis xav tau cov qauv nyias nyias; Cov duab muaj kev nkag siab zoo ntawm stereoscopy; Nws tuaj yeem txheeb xyuas qhov sib xyaw ntawm cov khoom siv cov ntaub ntawv xws li cov khoom siv hluav taws xob thib ob, cov khoom siv hluav taws xob nqus, thiab X-rays tsim los ntawm kev sib cuam tshuam ntawm cov kab hluav taws xob thiab cov khoom siv.
Kev tsim ntawm scanning electron microscopy yog nyob ntawm kev sib cuam tshuam ntawm electrons thiab teeb meem. Thaum tib neeg lub zog loj ntawm cov hluav taws xob tawg rau saum npoo ntawm cov khoom, thaj tsam zoo siab yuav tsim cov khoom siv hluav taws xob thib ob, Auger electrons, cov yam ntxwv thiab X-ray txuas ntxiv, thim rov qab electrons, xa hluav taws xob, thiab hluav taws xob hluav taws xob hauv qhov pom, ultraviolet, thiab thaj tsam infrared. Nyob rau tib lub sijhawm, electron hole khub, lattice vibrations (phonons), thiab electron oscillations (plasma) kuj raug tsim.
