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2017.07.07 

 

b.

 

Also  on  the  first  Parameters 
page  is  the  Emission  setting. 
Increase  the  filament  current 
to  the  saturation  value  by 
TURNING the Filament knob on 
the control panel which should 
ordinarily be left at 1. A higher 
value  will  produce  a  brighter 
beam  image  but  will  also 
shorten 

the 

lanthanum 

hexaboride (LaB6) filament life. 
 

4.

 

TEM Observation 

a.

 

VERIFY  the  Vacuum 
(both  UHV  and  HIVAC 
lights  are  illuminated 
and the IGP is <20 Log). 

b.

 

Log in to the PC with the 
Username 

and 

Password: femr. 

 

 

 

 

 

 

 

 

 

 

 

 

 

Содержание CM200

Страница 1: ...rtega Safety Do not wander behind the microscope or step on cables There is one computer for the CM200 TEM 1 The support PC SPC is for taking digital images with the AMT XR41B CCD camera and collecting spectra with the EDAX Genesis Energy Dispersive Spectrometer EDS and Genesis software Note Ensure you copy your data at the end of each TEM session Data older than three months may be deleted withou...

Страница 2: ...aminator cold finger dewar cold trap with liquid nitrogen The first dewar flask of the day should last 30 to 40 minutes Later dewars will each last 2 to 3 hours Do NOT allow the cold finger to fall below 50 or to warm up as the column vacuum will deteriorate significantly REPLACE the styrofoam cap on the top of the dewar The CRT screen will display the CM200 status startup page or more likely one ...

Страница 3: ...n to RETURN to the TEM Brightfield page black arrow VERIFY the Apertures Condenser Aperture C2 is at 4 Objective Aperture is 3 and the Selected Area Electron Diffraction SAED Aperture is out position of the lever is to the right except when performing electron diffraction 2 Specimen Loading and Holder Insertion Removal Note the specimen holder airlock and CompuStage are delicate precisely machined...

Страница 4: ...t to scrape it along the inside of the airlock Do NOT to touch the holder O ring or any part to the tip with bare hands B Specimen Loading Note NEVER mount magnetic samples or discs in the clamp holder of the Single Tilt Sample Holder The clamp spring is not strong enough to prevent the specimen from attaching to the objective lens polepiece Use the Double Tilt Sample Holder for magnetic samples N...

Страница 5: ...s using a sheet of Kimwipe C Inserting the Sample Holder into the CompuStage a Carefully ORIENT the Airlock Sample Holder Pin on the sample holder with the 5 o clock position on the CompuStage and gently INSERT the holder into the Airlock Entryway until it stops Be careful NOT to scrape the tip on the inner mechanism of the goniometer You should feel some resistance as the sample holder O ring sea...

Страница 6: ...value is lower than 20 Log h VERIFY the apertures inserted are correctly inserted Condenser Upper and Objective Middle apertures are inserted lever to the left and the dial at number 3 The Selected Area Electron Diffraction SAED aperture lower should be retracted lever to the right 3 High Tension Accelerating Voltage and Filament Saturation a To select the accelerating voltage High Tension PRESS t...

Страница 7: ...Filament knob on the control panel which should ordinarily be left at 1 A higher value will produce a brighter beam image but will also shorten the lanthanum hexaboride LaB6 filament life 4 TEM Observation a VERIFY the Vacuum both UHV and HIVAC lights are illuminated and the IGP is 20 Log b Log in to the PC with the Username and Password femr ...

Страница 8: ...ait rotate again for two clicks wait repeat until reaching 3 8 e OPEN the valve from Close to Open counterclockwise to the right of the microscope You should see the electron beam on the fluorescent screen Move the region of interest of your sample to the middle of the viewing area with the Joystick f On the TEM control panel PRESS the Auto Focus button g On the AMTV600 window CHANGE the setting f...

Страница 9: ...nhomogeneity and optical imperfection i VIEW the electron beam on the TEM viewing screen ii CENTRE the beam iii REMOVE specimen from column or locate a hole on TEM grid iv SET the magnification to roughly the magnification you will take the images v SPREAD the beam with C2 control clockwise so that the current is about 1 0 second on the exposure meter vi LIFT the viewing screen and cover the viewi...

Страница 10: ...with Caption 7 Eucentric Height Adjustment a Using the Magnification knob SET the Magnification to 5 800x and the use the Joystick to locate and centre a small feature on the TEM grid i e small hole or particle b FOCUS the feature using the Step Size knobs The Outer Knob changes the Focus and the Inner Knob i e the step size adjustment modifies the amount of focus change per click of the Outer Kno...

Страница 11: ...e Ready button to return to TEM Brightfield 8 Beam Alignment a USING the Magnification knob select a magnification of 17 500x b PRESS the Modes key on the CRT screen to access the Mode Selection page and then PRESS Configuration The Configuration page displays the Filament Heating status and provides a schematic of the available apertures Aperture Memo for the condenser 2 C2 objective and selected...

Страница 12: ...hese steps c and e until the beam spreads uniformly around the reference circle while being overfocused Intensity knob f USING the Intensity knob adjust the beam to crossover PRESS the Fine button to the left of the Intensity knob the indicator light turns green when it is on and use the Intensity knob to sharpen the desaturated filament image CENTRE the image using the Shift X Y knobs g PRESS the...

Страница 13: ...ts Staff only are authorized to access the Procedures which are long and complicated c USING the Intensity knob ADJUST the beam to crossover d PRESS the beamcoils Pivot Point X key on the right side of the page so that it is highlighted e USING the Multifunction X Y knobs bring the two beam spots the pivot points on the phosphorescent viewing screen together so that they overlap f CENTRE the coinc...

Страница 14: ...eature shifts off center laterally the beam is not aligned along the optical axis of the microscope and must be corrected b USE the Multifunction X Y knobs to stabilize the feature at the centre of the screen eliminating all lateral movement The feature should appear to be pulsating c PRESS the Algn button to return to the TEM Brightfield page B Current Centering a On the lower right hand side of ...

Страница 15: ...ot It may also be necessary to adjust the Intensity knob f INSERT the Objective Aperture by ROTATING the aperture displacement lever below it to the left 7 Apertures may be selected by rotating the largest knurled knob on the objective aperture assembly to any one of four numbered positions The Aperture Memo lists the diameters and positions of the apertures currently installed in the CM200 It may...

Страница 16: ... 175 000x or higher and adjust the illumination so the substructure or background grain i e carbon support film may be observed easily The Intensity will have to be modified and the electron beam recentered using the Shift X Y knobs Deflectors as the magnification is increased This latter function may alternatively be controlled using the RST button on the panel to the left of the column b SET the...

Страница 17: ... and Genesis Software A Collect spectra a DOUBLE CLICK on the EDAX Genesis icon on the PC desktop to open the program b TILT the goniometer by 15 c It is important to optimize the counts per second CPS and dead time DT d To change the CPS change the Spot Size Spot Size 6 is recommended e Generally to change the DT adjust the Amp Time DT should be between 20 to 40 As a rule of thumb SELECT an Amp T...

Страница 18: ...he toolbar and these controls are shown in the figure below The spectrum display may also be adjusted by clicking and dragging with the mouse b PRESS Clear All in the spectrum collection panel to remove any old peak labels c PRESS the Peak ID button in the Spectrum Panel for automatic peak identification The primary peaks identified by the program will be labeled on the spectrum d PRESS HPD to dis...

Страница 19: ... button at the bottom of the Spectrum Panel If you use the spc as the extension all the spectrum information will be saved and can be reanalyzed at a later time It is recommended that you save all your work with this format b To save an image of the spectrum Save As using the tif extension c When completed close the program 14 Changing samples a SELECT the TEM Brightfield page b PRESS the CompuSta...

Страница 20: ...elow the dewar platform to collect condensing moisture b On the CRT GO to the Vacuum page PRESS the Cryo key SET the time for six hours and PRESS the Start key C Retrieving Images from the Support PC SPC Note Files are deleted on the SPC every three months a COPY your images to a USB drive LOG OFF the SPC and TURN OFF monitors b CLOSE the AMTv600 program and LOG OUT of the PC c TURN OFF the Panel ...

Страница 21: ...Lλ for SAED For L 240 mm Lλ 73 6 mm Å For L 340 mm Lλ 104 1 mm Å For L 470 mm Lλ 146 4 mm Å For L 700 mm Lλ 204 4 mm Å Camera Constant Lλ for NBD For L 240 mm Lλ 57 5 mm Å Note that you MUST print out the diffraction pattern in FULL SIZE ...

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