Hitachi HT-7700 TEM

Nanoscale Imaging of Inorganic Materials

The HT7700 is an advanced Transmission Electron Microscope for imaging nano-material specimens. There are separate modes for low magnification/ High Contrast (HC) imaging and high magnification/ High Resolution (HR) imaging. The TEM utilizes modern computer control and digital cameras to enhance user-friendliness. Standard TEM grid sizes are a 3.05 mm diameter ring and samples must have a thickness of less than 100 nm. Applications: >TEM operation and viewing are integrated into user interface, allowing for operation of the TEM in ambient room lighting. Specifications: > Accelerating Voltage 40 ~ 120 KV >Resolution (lattice) 0.204 nm (100KV) >Magnification x200 ~ x200,000 (HC mode) x4,000 ~ x600,000 (HR mode)

If you would like training on the HT-7700 and have a GTLogin; click HERE and click on the request training button.

If you do not have a GTLogin click HERE.

 

 

Hitachi-HT7700 TEM Operation

No magnetic samples!!!

NO Organic/bio samples!!!!!

 

Initial conditions:
o Check cooling water level      o Check Vacuum system          o HV On (120 kV)

  1. Load your sample
    (a) Check of specimen stage coordinates
    – “Operation” -> “stage operation
    – set the specimen stage at the home position (x, y, α = 0)

(b) Remove the sample holder form the microscope
– hold the handle and pull straight back
– turn the specimen holder clockwise 15°
– pull back again
– turn the specimen holder counterclockwise 30°
– turn the “EVAC-AIR” switch to “AIR”, wait for about 10 seconds (Two sounds)
– remove the sample holder (avoid touching the sample holder beyond the O-ring)

(c) Specimen setting in specimen holder
– fix the holder with the holder fixing table
– shift the retainer spring with tweezers and stop it by hooking onto the stepped part
– separate the specimen retainer with tweezers and place the specimen
– place the specimen retainer aligning it with the groove
– use tweezers to raise the retainer spring while pulling it for its separation from the stepped part
– bring the retainer spring to the specimen retainer fixing position

(c) Insert the sample holder
– set specimen holder in the specimen exchange chamber
– turn the “EVAC-AIR” switch to “EVAC
– evacuation completed (green lamp lit)
– turn the specimen holder clockwise 30°; holder is inserted up to retraction point
– turn the specimen holder counterclockwise 15°; holder is inserted up to viewing position

  1. Turn on the filament/beam
    (a) Turn on the filament voltage (if the filament voltage is off)
    – “Operation” -> “HV/Filament Operation
    – click “Filam. on”, it takes about 30 seconds
    (b) Turn on the beam
    – Select Auto mode, click “Beam On
    under Auto mode, the filament current will automatically turn on and turn off when you
    loading or remove the sample holder
    (c) Click Run, to turn on the screen camera. (Left display)
  2. Specimen height adjustment
    (a) Push “Lens reset” button on the operation panel Once
    (b)At 20 kx, find a feature near the middle of the viewing screen
    (c) Press the “WOB” button on the operation panel;
    (d) Adjust image focus by manipulating the Z control knob of the specimen stage
    the image on the screen should remain steady, cancel “WOB” button
  3. Center the Beam (if the beam is not centered)
    Push the “BH” button, adjust the Beam centre by using the X, Y knobs on the operation panel.
  4. Start acquiring TEM images (Please always keep attention to the exposure intensity)
    (a) Find your sample using the Screen camera (Left display)
    You can use HC (>0.2K) mode to search your sample at the beginning, then change to HR mode (> 4 K) for getting images
    (b) Lower the beam intensity and click “Scr. out
    (c) Open the “Gatan Digital Micrograph” software (Right display)
    (d) Click “Start View” to start the image acquisition
    Put the cursor in the blank area of the image window, adjust the intensity 2,000~3,000.
    (e) Use “Focus” on the operation panel to adjust the focus of the sample
    (f) Click “Start Acquire” to record the final image
    (g) Click “File” –> “Save Display As” to save your image
    (h) Switch to Screen camera: Click “Stop View”, then “Scr. in” (left display), double click
    Link Screen”.
    Before changing samples, please reduce magnification to 4 K and set the spacemen stage at the home position (x, y, α = 0)

Session shut down:
o Reduce magnification to 4 K
o Set the spacemen stage at the home position (x, y, α = 0)
o Remove the sample from the specimen holder, and store the holder in the standby position
o Click “Beam off” to turn off the beam
o Exit “Gatan Digital Micrograph” software
o Stop the Screen camera (if there are no users right after you)
o Click “Film off” to turn off the filament voltage (if you are the last user of the day)