Home
HRTEM Imager

The HRTEM imager allows to load a wave-function and to calculate HRTEM images. The imager does not require loading a crystal file since it uses the metric and geometry stored in the wave-function file. The wave-function are calculater either using the Bloch-wave or the multislice methods. Using the Bloch-wave method the illunimation tilt or crystal tilt can be changed in real-time.

Figure1

Figure 1 HRTEM imager.

The toolbar contains tool buttons to:

Figure2

Figure 2 Contrast transfer Function and rotational average.

Figure3

Figure 3 Wave-function (phase image).

Controls are placed in 12 panes and are used to include the:

Figure4a Figure4b

Figure 4a Camera MTF.

Figure 4b Aberrations.

Figure5a Figure5b

Figure 5a CLC (crystal tilt).

Figure 5b Spatial and temporal coherence.

Figure6a Figure6b

Figure 6a Dark Field (illumination tilt (12,36,0)).

Figure 6b HRTEM image under DF conditions.

Figure7a Figure7b

Figure 7a Bright Field (illumination tilt (0,0,0)).

Figure 7b HRTEM image under BF conditions.

In order to modify defocus (or any aberration coefficient to order 8) move the mouse in the control and change the value either entering a new value or using the keyboard ↑ or ↓ arrows to increase or decrease its control. keys combined with Alt, Shift or Meta keys to speed up the changes.

Note that the formula box displays the wave-Aberrations (see HRSTEM imager).

Figure8

Figure 8 HRTEM imager can introduce the contrast damping effect of the Modulation Transfer Function of the camera.

The camera MTF can be measured using menu item Camera MTF (menu Measuring).

Figure9a Figure9b

Figure 9a Camera CCD MTF at low magnification.

Figure 9b Calculated HRTEM image taking into account the MTF of the camera (Gatan MSC-1Kx1K, 24 μm) image contrast 0.93.

Figure10a Figure10b

Figure 10a Camera CCD MTF at high magnification.

Figure 10b Calculated HRTEM image taking into account the MTF of the camera (Gatan MSC-1Kx1K, 24 μm) image contrast 2.4.

When a camera id selected and the MTF displayed, the TEM magnification slider changes the magnification (on the camera) and introduces the MTF contrast damping (Stobbs factor ?).

Figure11

Figure 11 A list of camera MTF can be loaded and selected.

Figure12

Figure 12 HRTEM imager displaying the image and wave-function duplicated 4 times in x and y directions.