Txoj cai thiab daim ntawv thov ntawm Scanning electron microscope
Piv nrog rau optical microscopy thiab kis electron microscopy, scanning electron microscopy muaj cov yam ntxwv hauv qab no:
(1) Muaj peev xwm saib xyuas cov qauv saum npoo ntawm cov qauv, nrog rau cov qauv loj txog li 120mm × 80mm × 50mm.
(2) Cov txheej txheem kev npaj ua qauv yog yooj yim thiab tsis tas yuav txiav rau hauv nyias nyias.
(3) Cov qauv tuaj yeem muab txhais thiab tig rau hauv peb qhov loj me hauv cov qauv chamber, yog li nws tuaj yeem pom los ntawm ntau lub kaum ntse ntse.
(4) Qhov tob ntawm daim teb yog loj, thiab cov duab yog nplua nuj nyob rau hauv peb-dimensional kev nkag siab. Qhov tob ntawm daim teb ntawm scanning electron microscopy yog ob peb puas lub sij hawm loj dua li ntawm optical microscopy thiab ob peb kaum ntawm lub sij hawm loj tshaj qhov kis tau tus mob electron microscopy.
(5) Lub magnification ntau yam ntawm daim duab yog dav, thiab cov kev daws teeb meem kuj kuj siab. Nws tuaj yeem nthuav tawm los ntawm kaum mus rau ntau pua txhiab zaus, thiab nws yeej suav nrog qhov kev nthuav dav los ntawm lub iav tsom iav, tsom iav tsom iav mus rau lub tshuab hluav taws xob xa hluav taws xob. Qhov kev daws teeb meem yog nruab nrab ntawm optical microscopy thiab kis tau tus mob electron microscopy, ncav cuag li 3nm.
(6) Kev puas tsuaj thiab paug ntawm cov qauv los ntawm cov kab hluav taws xob yog qhov me me.
(7) Thaum soj ntsuam cov morphology, lwm cov cim qhia tawm los ntawm cov qauv kuj tuaj yeem siv rau kev txheeb xyuas thaj tsam micro.
Tus qauv thiab lub hauv paus ntsiab lus ua haujlwm ntawm scanning electron microscopy
(1) Qauv 1. Daim iav raj
Lub lens chim muaj xws li phom electron, condenser, lub hom phiaj, thiab scanning system. Nws txoj haujlwm yog tsim kom muaj cov kab hluav taws xob zoo heev (nrog rau txoj kab uas hla ntawm ob peb nanometers), thiab ua kom cov kab hluav taws xob xaim hluav taws xob nyob rau saum npoo ntawm cov qauv, thaum txhawb ntau yam teeb liab.
2. Hluav taws xob teeb liab sau thiab kev ua haujlwm
Nyob rau hauv cov qauv chamber, lub scanning electron beam interacts nrog cov qauv los tsim ib tug ntau yam ntawm cov teeb liab, xws li Secondary electrons, backscattered electron, X-ray, absorption electron, Auger electron, thiab lwm yam. Ntawm cov saum toj no cov cim, qhov tseem ceeb tshaj plaws yog lub Secondary electrons, uas yog sab nraud electron nyob rau hauv tus qauv atom zoo siab los ntawm qhov teeb meem electron, generated nyob rau hauv thaj tsam ntawm ob peb nm mus rau kaum ntawm nm hauv qab tus qauv nto, thiab nws cov nqi ntau lawm yog nyob ntawm morphology thiab muaj pes tsawg leeg ntawm cov qauv. Feem ntau hais lus, cov duab hluav taws xob scanning yog hais txog Secondary electrons duab, uas yog qhov tseem ceeb tshaj plaws hauv hluav taws xob teeb liab rau kev kawm txog qhov chaw morphology ntawm cov qauv. Qhov kev sojntsuam ntawm lub tshuab kuaj xyuas kom pom cov khoom siv hluav taws xob Secondary (Fig. 15 (2)) yog lub tshuab scintillator. Thaum lub electron tsoo lub scintillator, 1 generates lub teeb nyob rau hauv nws. Lub teeb no kis tau los ntawm photoconductor mus rau Photomultiplier raj, thiab cov teeb liab kho qhov muag tau hloov mus rau hauv lub teeb liab tam sim no. Tom qab ua ntej amplification thiab video amplification, lub teeb liab tam sim no hloov mus rau hauv lub teeb liab voltage, thiab thaum kawg xa mus rau daim phiaj ntawm daim duab raj.
