-
SCANNING ELECTRON MICROSCOPE WITH ENERGY DISPERSIVE X-RAY SPECTROMETER (SEM-EDAX)
... ..
.
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(SEM/EDAX)
/ I.
1.
(Scanning Electron Microscopy, SEM) .
1000x 0.2 m. 30 (, .) 10,000 x. . (TEM, Transmission Electron Microscope) (SEM, Scanning Electron Microscope).
, . (.. ). . . (secondary) (backscattered) . . SEM . , . SEM .2.
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4 .
1) (emission current)
2) (spot size)
3) / (accelerating voltage)
4) ( )
2 :
1) (Charging) ( )2) ( , )
3)
( , )
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(Elastically scattered primary electrons) . (Backscattered Electrons) 30 KeV . . ( ) ( 50 80% ). 180 (Backscattered electrons, BSE). .
, . ~6% ~50%. S . . .
(solid state semiconductor) donut, . .
2.2
(Inelastically scattered electrons), (Secondary electrons, SE)
. ( ).
.
(50eV) , . .
. . .
(+100V) . . (CRT), . .
2.3
(X-Rays): (Bremsstahlung) (Characteristic)
Auger
, ( ) Bremsstahlung. . .
. , . .
( ) . , , eV (Multi Channel Analyzer). (Look Up Table) .
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Auger
Auger .3. SEM . , , . :
1)
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3) .
.
3.1
( ), .
(filament current). , 1-30 KV (accelerating voltage). . , .
, . (filament saturation). , , . , . (emission current 100 ). (filament tip) (Wehnelt cap aperture). .
(condenser lens) ( ). (spot size).
. : () (). . , :
S
, f . , . , , .3.2
SEM, . . 2e-3 Pa. 3.3
(--). Everhart Thornley (ETD), (Large Field Detector, LFD), (Gaseous Electron Dtector GED), (Solid State Electron Detector, SSED) (BSE), (SiLi), - (Energy Dispersive Spetrometer, EDS).
4. . , , , , , , , , , , , . , SEM . . SEM XRD , , , .
, . SEM..
1.
. , . , , . , . , , .
, , . , . , , . , .
2.
Quanta 200 FEI -EDAX. Quanta 200 100,000x 6 nm.
Quanta 200 :
(High Vacum 2e-3 Pa)
(Low Vacum 3-12 Pa)
(ESEM, Environmental Scanning Electron Microscopy) - .
, 2cm 5cm x,y,z . ( ): Everhart Thornley (ETD), Large Field Detector (LFD), Gaseous Electron Dtector (GED), Solid State Electron Detector (SSED) (EDX). :
EDAX Genesis. . . . .
1. Principles of Instrumental Analysis Skoog, Holler, Nilman, Harcourt College Publishers, 1998
2. Analytical Chemistry R.Kellner, J.M.Mermet, M.Otto, H.M.Widmer, Wiley-VCH, 1997
3. mse.iastate.edu/microscopy/home.html
4. www.mos.org/sln/SEM/5. science.nasa.gov/newhome/headlines/ast05mar98_3.htm
6. www.sciencemuseum.org.uk/on-line/electron/section4/sem.asp7. acept.la.asu.edu/PiN/rdg/elmicr/elmicr.html
8. www.wiley.com/cp/mmr/mmrsampl.htm
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