5 OPERATION
5-44
EM210F-1
5.5.2 Microbeam Electron Diffraction
A finely converged electron beam, illuminating only a very small area on the specimen,
forms a diffraction pattern in this method (also called “microarea”, “nanoarea”, or
“converged” electron diffraction).
1.
Obtain a conventional image on the screen.
2.
Depress the MAG1 (R1-
③
), and select the desired magnification in the TEM
mode.
3.
Select a magnification to be used using the MAG-CAM L knob (R1-
⑤
).
4.
Bring a field of view to be used to the screen center using the triangle buttons
or trackball (
F
Sect. 4.2.5).
5.
Focus the image using the OBJ FOCUS knob (R1-
⑥
).
6.
Carry out the multiple-exposure (
F
Sect. 5.2.6d) to carry out the first
photograph.
7.
Depress the NBD switch (L1-
③
) to obtain the NBD mode.
8.
Converge the beam using the BRIGHTNESS knob (R1-
⑥
).
9.
Manipulate the SPOT SIZE knob (L1-
③
) to select the spot size value.
10.
Move the electron beam to the field to be studied using the left and right
SHIFT (L1-
⑧
, R1-
③
).
11.
Depress the SA DIFF (R1-
②
).
12.
Select a camera length using the MAG-CAM L knob (R1-
⑤
).
13.
Adjust the size of the diffraction spot by varying the
a
-SELECTOR knob (L1-
③
) and changing the condenser aperture size.
14.
Depress the MAG1 switch (R1-
②
) to obtain the MAG mode.
15.
Carry out the second exposure in the multiple-exposure mode.
16.
Depress the SA DIFF switch (R1-
②
).
17.
Record the pattern in the manual exposure mode (the exposure time of about
30 seconds will be suitable).
a: Beam spot and image
b: Microbeam diffraction pattern
Fig. 5.40 Microbeam electron diffraction
