JEOL FX.docx

1、JEOL FXJEOL 2000FX With thanks to Professor John F. Mansfield from the University of Michigan upon who provided the handbook upon which these instructions are based.Preamble1. Note that the microscope is a state-of-the-art research instrument and should be treated with great care because a large num

2、ber of people rely on it for their day-to-day work.2. With the above comment in mind, before you do anything to the microscope, i.e. insert or withdraw a specimen or detector, THINK and determine whether your action is liable to compromise any of the functions or accessories of the microscope.3. In

3、the instructions that follow you should monitor the vacuum status of the instrument on the ion-gauge meter and/or the Penning gauge while you are performing any action that may change the level of vacuum inside the microscope. If the vacuum changes radically and abnormally when you start to do somet

4、hing, STOP and reverse your actions, wait for the vacuum to recover and determine why there is a problem. This will usually involve consulting Gabriella Chapman, John Lynch or Ron Doole. Do not hesitate to contact one of them if you are unsure of what to do in any particular situation. Starting Up C

5、heck vacuum It should be less than 10 x 10-5 Pa on the ion-pump power supply behind the microscope. If you wish to use the anti contamination device please see Gabriella Chapman or John Lynch for instruction. At present the microscope requires a modification before it can be used. Load your specimen

6、, - Put on some gloves.To limit unwanted contaminants in the specimen environment of the microscope, always wear gloves when handling the specimen holders, do not touch any part of the metal rod of the holder with your bare hands. Although only part of the rod actually enters the vacuum of the micro

7、scope, grease and other contaminants from your hands (if you do not wear gloves) may be transferred along the specimen rod to the section that is inserted into the vacuum system. - Zero the X, Y tilts. Zero the X, Y specimen position. Lock goniometer. Make sure the filament is off and all detectors

8、are fully retracted.- Remove the specimen holder from the microscope. Pull the holder out until it stops, rotate anticlockwise and ease out.- Turn the sample holder upside down and tap gently on the back end (away from the sample) to make sure your sample will not fall out in the microscope.- Always

9、 inspect the o-ring before inserting the holder into the microscope, as they tend to pick up hairs, dust, etc. Wipe with a gloved finger. Do not grease the specimen holder o-rings without first consulting Gabriella Chapman or John Lynch.- Insert the specimen holder straight into the microscope witho

10、ut turning it. (If you turn the holder you will allow air into the column). It should trigger a micro switch that starts the pump down cycle. You may have to push the holder against the micro switch to trigger it (dont turn the holder!). - Pump for a minimum of three cycles and a maximum of five bef

11、ore inserting. You MUST wait for three cycles! Do not insert sample holder if the red light is on. These cycles may take longer if the film has just been changed. Insert the rod by rotating clockwise and allow the vacuum to pull the holder in - do not release it until it is all the way into the micr

12、oscope. - If the vacuum does not recover within a short time, check to see if the film was changed in the last hour. If not, the holder o-ring may be dirty, remove the holder and clean the o-ring with a lint free wipe. Turning up the HTBefore switching on the HT check the vacuum is less than 10 x 10

13、-5Pa.Start the HT at 160kV. The HT may be changed with the white rocker switch, which is above the HT on/off switch. The amount by which the HT changes each time you click the rocker switch may be set on the keyboard. Type HT and then the required step size (e.g. 05) on the keyboard. The size is dis

14、played on the bottom line of the display as you type. After turning the HT on at 160kV, set the step size to 5 kV and bring the voltage up to 190kV. Wait a couple of seconds after each 5kV click to ensure the vacuum reading on the ion-gauge does not rise. At 190kV change the step size to 1kV, and co

15、ntinue to raise the voltage to 200kV, checking that the vacuum level in the column does not change significantly. If the vacuum does change, wait for it to recover before increasing the voltage further. If there is a very large change in the vacuum level or if there is a discharge in the gun seek he

16、lp.The dark current should read 103 and no more than 105 at 200 kV. If it reads 000, the HT is off. Filament heating:Start to heat the filament when the vacuum is less than 10 x 10-5 Pa.Increase the filament heating to saturation SLOWLY taking about 2 minutes in all. Generally there is still some de

17、tail in the filament even when it is saturated. The stop is set at the usual saturation point for the current filament. It is usually between 109-114 A. (emission current at 10A above dark current from cold and after 30mins to 1hr 5-8A above dark current).If you have reached the stop and there is no

18、 beam on the screen, see the next section (“Aligning the Microscope for General Use”, step 0.) to find the beam.DO NOT CHANGE THE BIAS seek help if you think it needs resetting.If the brightness of your image seems low (look at a hole in your specimen to be sure the brightness problem is not really

19、just a specimen thickness problem) or if the exposure times for your pictures are too long, please ask for advice on how best to proceed.- Always turn the filament down to zero before removing the specimen from the microscope.- Turning down the filament should be a slow and continuous process, takin

20、g about 30-60 seconds. It is not necessary to take as long as when initially heating.Shutting down Withdraw the objective and selected area apertures. Leave largest condenser aperture inserted lever to the left TEM image mode. Spot size 2L. Mag 15kx. Spread beam to just fill the large screen. X,Y ti

21、lt to zero. Lock goniometer. X,Y position to zero. Turn the filament to zero before removing the specimen from the microscope. Turning down the filament should be a slow and continuous process, taking about 30-60 seconds. It is not necessary to take as long as when initially heating. Turn the HT off

22、. Turn the magnification back up to 100kx. Remove your specimen pull the sample holder to the stop, rotate counter clockwise, ease out with thumb. Insert the empty specimen rod into the microscope. Change exposed plates if you used any film. It is better to do this after the specimen rod is back in

23、the microscope, otherwise the vacuum will take much longer to pump down. Turn off the panel lights and CRT screen. Sign the log book. Do not turn off the microscope.Aligning the Microscope for General Use0. Find the beam The last user should have left the microscope with the beam just filling the sc

24、reen at a magnification of 5-20kX. If you cant see any beam, the most likely reason is that your sample is in the way try moving it around. DO NOT move apertures, gun tilt/shift or beam shift to find the beam! If you cant see the beam, try the following (approximately in order): Check that the filam

25、ent bright current has reached the normal value (109-114). The filament heater should be at the stop. DO NOT MOVE the stop position. Check the spot size is 2L. Decrease the magnification and spread the beam. Check that the objective and selected area apertures are out. DONT MOVE the X and Y knobs! I

26、f you know you should have a hole approximately in the centre of your specimen or you have a grid, move the specimen a little until you see the hole. Watch the specimen position on the microscope computer screen. Go to low mag. mode and spread the beam. Move your sample to find the hole. The 2000FX

27、has a two-sample holder. If someone has used this before you, it may be set at position 1 or 2. For a single specimen holder, the position should be in the middle. The adjustment is on the left side of the microscope column. It is a knurled wheel with a position marker. If you still cant see the bea

28、m, go and get help.1. Filament Alignment Beam on screen, Magnification at 20Kx, Spot Size at 2L (Page 1 of microscope display). Choose an appropriate condenser aperture. With the lever to the left the sizes are 200, 120 and 70m. Adjust the Gun Align Tilt for maximum brightness. (right drawer) Bring

29、Brightness to crossover and centre the beam with Gun Align. Shift X, Y. (right drawer) Adjust Gun Align. Tilt for maximum brightness. 2. Gun/Condenser Alignment Change Spot Size to 4L. (spot size toggle switch on left panel) Bring Brightness to crossover and centre beam with Beam Shifts X,Y. Switch

30、Spot Size back to 2L. Bring Brightness to crossover and centre the beam with Gun Alignment Shifts X,Y. Repeat until beam remains centred for both spot sizes. Recentre Gun Tilt as in 1 above (tilt for max. brightness).Centre beam from now on with Beam Shifts, NOT Gun Alignment Shifts3. Condenser Aper

31、ture Centring Centre beam on screen at crossover with Beam Shifts X,Y. Watch for beam swing when spreading the beam with Brightness either side of crossover. If beam swings away from centre when spread, correct by centring the condenser aperture.4. Condenser stigmation Correct condenser lens astigma

32、tism with condenser stigmator (button left panel; def X,Y)5. Optimum Objective Focus./ Adjust Z Axis (Eucentric Correction)Coarse Adjustment: Set OBJ Lens current (read on Page 4) in the region of 7.00 to 7.05 at 200kV (5.21 at 120kV) using Objective focus knob (right panel). Locate specimen and centre a feature at a Magnification of 15Kx or less. Focus the image using the Z height adjust knob. (up near the specimen