How to capture HRTEM images (Mag > 500k)

How to capture the HRTEM images (Mag > 500k)

  1. At 100k X magnification, adjust the "Obj Focus" knob so that the DV is slight +0 from -0.

  2. Under WOBBLER, activate IMAGE X or IMAGE Y (only one). Use "Z up" and "Z down" to minimize the image movement (shaking). You may insert the small viewing screen with the binocular.

  3. Deactivate the "IMAGE X" or "IMAGE Y" when finished.

  4. Use Selector to increase magnification further > 500kX.
    For HRTEM: You may observe the lattice fringe when magnification is ~ 800kX (scale bar is ~5 nm).
    1.5 M X is the maximum limit of the TEM.

  5. Press “Screen” to lift the screen so that the electron beam can reach the CCD detector.

  6. On the software, click “Start View”. Select suitable exposure time, like 0.5 seconds.

  7. Focus image with "Obj Focus" fine knob using Live FFT.

  8. To capture the image click “Start Acquire” or “Stop View”, then save the image in Gatan Format “.dm3”.

Notes:

  1. A focused image should have......
    -    Sharp features
    -Minimal contrast (at the thinnest part of the sample)
    -No bright/dark fringe at the edge of the sample
    -No diffraction ring present in the FFT

2. FFT is preferred for high magnification (>125k).
Turn the "OBJ Focus" knob to maximize the diameter of the inner circle of FFT.