Taw qhia rau cov ntawv thov tseem ceeb ntawm scanning electron microscopy
Scanning electron microscope yog cov cuab yeej siv ntau yam nrog ntau cov khoom zoo tshaj plaws thiab yog ib qho ntawm cov cuab yeej siv dav tshaj plaws, uas tuaj yeem ua cov kev ntsuam xyuas hauv qab no:
(1) Kev soj ntsuam thiab kev soj ntsuam ntawm peb-dimensional morphology;
(2) Kev tsom xam ntawm micro-regions thaum saib morphology.
(1) Kev soj ntsuam ntawm nanomaterials. Cov khoom hu ua nanomaterials yog cov khoom siv uas tau txais los ntawm kev txhaj tshuaj molding nyob rau hauv cov xwm txheej ntawm kev ua kom lub ntsej muag huv si thaum qhov loj ntawm cov khoom siv los yog microcrystals tsim cov khoom nyob rau hauv thaj tsam ntawm 0.1 mus rau 100 nm. Nanomaterials muaj ntau yam physicochemical tshwj xeeb uas txawv ntawm cov crystalline thiab amorphous xeev. Nanomaterials muaj txoj kev loj hlob dav dav thiab yuav dhau los ua qhov tseem ceeb ntawm kev tshawb fawb cov ntaub ntawv yav tom ntej. Ib qho tseem ceeb ntawm scanning electron microscope yog nws cov kev daws teeb meem siab, uas yog tam sim no dav siv los soj ntsuam nanomaterials.
② Txhawm rau ua qhov kev soj ntsuam ntawm cov khoom tawg. Lwm qhov tseem ceeb ntawm lub tshuab ntsuas hluav taws xob ntsuas hluav taws xob yog qhov tob ntawm daim teb, cov duab yog nplua nuj nyob rau hauv peb-dimensional kev nkag siab. Scanning electron microscope qhov tob ntawm kev ua kom pom tseeb tshaj qhov kis tau tus mob electron microscope 10 lub sij hawm loj dua qhov kho qhov muag microscope ntau pua zaus. Raws li cov duab qhov tob ntawm daim teb yog loj, yog li cov duab electron scanning yog nplua nuj nyob rau hauv peb-dimensional kev nkag siab, nrog peb-dimensional daim ntawv, yuav muab tau ntau yam ntaub ntawv ntau tshaj li lwm yam microscopes, qhov no feature yog heev tseem ceeb rau cov neeg siv. Scanning electron microscope qhia cov pob txha morphology los ntawm qhov sib sib zog nqus, qhov siab ntawm lub kaum sab xis nthuav qhia cov ntsiab lus ntawm cov khoom tawg, hauv kev qhia, kev tshawb fawb thiab kev tsim khoom, muaj lub luag haujlwm irreplaceable hauv kev txheeb xyuas qhov ua rau ntawm cov khoom tawg, kev tsom xam ntawm cov ua rau muaj kev huam yuaj thiab cov txheej txheem tsim nyog yog ib qho kev txiav txim siab muaj zog.
③ Kev soj ntsuam ncaj qha ntawm thawj qhov chaw ntawm cov qauv loj. Nws tuaj yeem ncaj qha saib cov qauv nrog lub cheeb ntawm 100 hli, qhov siab ntawm 50 hli, lossis qhov loj dua, yam tsis muaj kev txwv ntawm cov qauv ntawm cov qauv, thiab cov npoo ntxhib kuj tuaj yeem pom, uas tshem tawm cov teeb meem ntawm kev npaj cov qauv, thiab tuaj yeem soj ntsuam cov qauv nws tus kheej raws li cov khoom siv sib txawv ntawm cov kab sib txawv (rov qab-reflected electron duab).
④ Kev soj ntsuam cov qauv tuab. Thaum soj ntsuam cov qauv tuab, nws muaj peev xwm kom tau txais kev daws teeb meem siab thiab qhov tseeb tshaj plaws. Qhov kev daws teeb meem ntawm scanning electron microscopy yog nyob nruab nrab ntawm qhov chaw kho qhov muag microscopy thiab kis electron microscopy. Txawm li cas los xij, thaum muab piv rau kev soj ntsuam ntawm cov qauv tuab, vim hais tias nyob rau hauv kev sib kis electron microscope, nws yog ib qho tsim nyog yuav tsum siv cov txheej txheem ua yeeb yaj kiab, thiab qhov kev daws teeb meem ntawm cov yeeb yaj kiab feem ntau tsuas yog 10 nm, thiab kev soj ntsuam tsis yog ntawm cov qauv nws tus kheej. , yog li ntawd, nws yog qhov zoo dua los soj ntsuam cov qauv tuab nrog lub tshuab ntsuas hluav taws xob kom tau txais cov ntaub ntawv tiag tiag ntawm cov qauv ntawm qhov chaw.
⑤ Saib xyuas cov ntsiab lus ntawm txhua qhov chaw ntawm cov qauv. Cov qauv muaj qhov loj heev txav tau nyob rau hauv cov qauv chamber. Qhov kev ncua deb ntawm lwm lub tshuab tsom iav feem ntau tsuas yog 2-3cm, yog li cov qauv tsuas yog tso cai txav mus rau hauv ob qhov chaw ntawm qhov chaw. Txawm li cas los xij, nyob rau hauv lub scanning electron microscope yog txawv, vim hais tias qhov kev ua hauj lwm deb yog loj (yuav ua tau ntau tshaj 20 hli), lub focal qhov tob yog loj (10 npaug loj dua lub kis tau tus mob electron microscope), thiab qhov chaw ntawm lub chav tsev qauv kuj yog. loj, yog li cov qauv tuaj yeem tso cai kom muaj rau qib kev ywj pheej ntawm kev txav mus los hauv peb qib ntawm qhov chaw (piv txwv li, peb qib ntawm qhov chaw txhais lus, peb qib ntawm qhov chaw sib hloov), thiab qhov ntau ntawm kev txav yog loj, uas yog qhov yooj yim heev rau kev soj ntsuam ntawm irregularly zoo li tus qauv ntawm cov ntsiab lus ntawm ntau lub cheeb tsam.
(vi) Kev soj ntsuam ntawm cov qauv hauv qab qhov loj ntawm qhov pom thiab qhov loj me. Lub teb ntawm kev saib xyuas cov qauv nrog lub tshuab ntsuas hluav taws xob scanning yog qhov loj. Hauv lub tshuab ntsuas hluav taws xob scanning, qhov chaw saib F, uas tso cai rau kev soj ntsuam ib txhij ntawm cov qauv, txiav txim siab los ntawm cov qauv hauv qab no: F=L / M [8].
Qhov twg F - thaj tsam ntawm saib ntau yam;
M - qhov loj ntawm kev soj ntsuam;
L - qhov loj ntawm lub vijtsam fluorescent ntawm lub raj.
Yog tias lub tshuab ntsuas hluav taws xob siv hluav taws xob siv lub raj 30 cm (12 nti), magnification 15 zaug, nws qhov chaw saib ntau txog 20 hli. qhov loj ntawm qhov pom, qhov tsis tshua pom kev pom ntawm cov qauv ntawm cov qauv yog tsim nyog rau qee qhov chaw, xws li kev tshawb nrhiav kev ua txhaum cai thiab archaeology.
(7) Kev soj ntsuam tsis tu ncua los ntawm qhov siab magnification mus rau qis magnification. Qhov ntau ntawm magnification yog dav heev thiab tsis tas yuav tsom mus rau ntau zaus. Scanning electron microscope magnification range yog dav heev (los ntawm 5 mus rau 200, 000 lub sij hawm tsis tu ncua adjustable), thiab ib tug zoo tsom xam yuav yog los ntawm siab mus rau lub sij hawm tsawg, los ntawm qis mus rau high zaus kev soj ntsuam mus tas li, tsis muaj refocusing, uas yog tshwj xeeb yooj yim rau kev soj ntsuam kev sib tsoo.
⑧ Kev soj ntsuam ntawm cov kab mob lom. Vim yog hluav taws xob irradiation thiab qhov tshwm sim ntawm cov qauv kev puas tsuaj thiab kev kis kab mob me me heev. Kev sib piv nrog rau lwm hom ntawm electron microscopy, vim hais tias qhov kev soj ntsuam ntawm lub electron sojntsuam siv nyob rau hauv tam sim no yog me me (feem ntau txog 10-10 ~ 10-12A) electron sojntsuam beam qhov chaw me me (feem ntau yog 5 nm mus rau kaum. ntawm nanometers), lub electron sojntsuam lub zog kuj tseem me me (ua kom ceev voltage yuav tsawg li 2 kV), thiab tsis yog ib qho chaw ruaj khov ntawm irradiation ntawm cov qauv, tab sis raster scanning txoj kev ntawm irradiation ntawm cov qauv, yog li ntawd, vim Yog li ntawd, qhov degree ntawm kev puas tsuaj thiab paug ntawm cov qauv vim yog electron irradiation yog heev me me, uas yog tshwj xeeb tshaj yog ib qho tseem ceeb rau kev soj ntsuam ntawm ib co kab mob lom.
