AFM vs SEM
Yuav tsum tau tshawb xyuas lub ntiaj teb me me, tau loj hlob sai nrog kev tsim kho tshiab tshiab xws li nanotechnology, microbiology thiab electronics. Txij li thaum lub tshuab microscope yog lub cuab yeej uas muab cov duab loj ntawm cov khoom me me, ntau qhov kev tshawb fawb tau ua tiav ntawm kev tsim cov txheej txheem sib txawv ntawm lub tshuab tsom mus rau kev daws teeb meem. Txawm hais tias thawj lub tshuab microscope yog ib qho kev daws teeb meem uas cov lo ntsiab muag tau siv los nthuav cov duab, tam sim no lub tshuab ntsuas ntsuas siab ua raws li kev sib txawv. Scanning Electron Microscope (SEM) thiab Atomic Force Microscope (AFM) yog ua raws li ob txoj hauv kev sib txawv.
Atomic Force Microscope (AFM)
AFM siv lub ntsis ntiv tes txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm Lub tswv yim no zoo ib yam li txoj hauv kev uas tus neeg dig muag nkag siab qhov chaw los ntawm kev khiav nws cov ntiv tes thoob plaws qhov chaw. AFM thev naus laus zis tau qhia los ntawm Gerd Binnig thiab Christoph Gerber hauv 1986 thiab nws tau muag txij li xyoo 1989.
Lub taub yog ua los ntawm cov ntaub ntawv xws li pob zeb diamond, silicon thiab carbon nanotubes thiab txuas rau lub cantilever. Me me qhov taub siab dua qhov kev daws teeb meem ntawm cov duab. Feem ntau ntawm AFMs tam sim no muaj kev daws teeb meem nanometer. Cov txheej txheem sib txawv yog siv los ntsuas qhov kev hloov pauv ntawm cantilever. Feem ntau txoj kev yog siv lub laser beam uas xav txog ntawm cantilever kom deflection ntawm lub reflected beam yuav siv tau raws li ib tug ntsuas ntawm cantilever txoj hauj lwm.
Vim AFM siv txoj hauv kev ntawm kev hnov ntawm qhov chaw uas siv cov tshuab sojntsuam, nws muaj peev xwm tsim tau cov duab 3D ntawm cov qauv los ntawm kev soj ntsuam txhua qhov chaw. Nws kuj tseem tso cai rau cov neeg siv los tswj cov atoms lossis cov molecules ntawm cov qauv saum npoo siv lub ntsis.
Scanning Electron Microscope (SEM)
SEM siv lub teeb hluav taws xob hloov lub teeb rau kev yees duab. Nws muaj qhov tob loj hauv thaj teb uas tso cai rau cov neeg siv los soj ntsuam cov duab ntxaws ntxiv ntawm cov qauv saum npoo. AFM kuj tseem muaj kev tswj hwm ntau qhov kev nthuav dav raws li kev siv hluav taws xob electromagnetic.
Nyob rau hauv SEM, lub nqaj ntawm electrons yog tsim los ntawm ib rab phom electron thiab nws mus los ntawm txoj kev ntsug raws li lub tshuab tsom iav uas muab tso rau hauv lub tshuab nqus tsev. Hluav taws xob thiab sib nqus teb nrog lo ntsiab muag tsom lub teeb hluav taws xob rau cov qauv. Thaum lub teeb hluav taws xob tsoo ntawm tus qauv saum npoo, electrons thiab X-rays raug tso tawm. Cov emissions no raug kuaj xyuas thiab tshuaj xyuas txhawm rau muab cov duab tso rau ntawm qhov screen. Kev daws teeb meem ntawm SEM yog nyob rau hauv nanometer scale thiab nws nyob ntawm lub beam zog.
Vim SEM ua haujlwm hauv lub tshuab nqus tsev thiab tseem siv cov khoom siv hluav taws xob hauv cov txheej txheem duab, cov txheej txheem tshwj xeeb yuav tsum ua raws li hauv cov qauv kev npaj.
SEM muaj keeb kwm ntev heev txij li thaum nws thawj qhov kev soj ntsuam ua los ntawm Max Knoll hauv xyoo 1935. Thawj qhov kev lag luam SEM muaj nyob rau xyoo 1965.
Qhov txawv ntawm AFM thiab SEM
1. SEM siv lub teeb hluav taws xob rau kev yees duab qhov twg AFM siv cov txheej txheem ntawm kev hnov ntawm qhov chaw siv cov khoom siv tshuaj ntsuam xyuas.
2. AFM tuaj yeem muab cov ntaub ntawv 3-dimensional ntawm qhov chaw txawm tias SEM tsuas yog muab cov duab 2-dimensional.
3. Tsis muaj kev kho tshwj xeeb rau cov qauv hauv AFM tsis zoo li hauv SEM uas muaj ntau yam kev kho mob ua ntej yuav tsum tau ua raws li vim lub tshuab nqus tsev thiab hluav taws xob nqaj.
4. SEM tuaj yeem txheeb xyuas thaj tsam loj dua piv rau AFM.
5. SEM tuaj yeem ua scanning sai dua AFM.
6. Txawm hais tias SEM tuaj yeem siv rau kev kos duab nkaus xwb, AFM tuaj yeem siv los tswj cov molecules ntxiv rau kev kos duab.
7. SEM uas tau tshaj tawm xyoo 1935 muaj keeb kwm ntev dua piv rau tsis ntev los no (hauv 1986) tau qhia AFM.
