SAED d value calculation
STEP2: Now enter the distance (in Angstrom) between two bright spots into “Distance between 2 bright spots” column of the calculator. You should get the calculated result of d value in the field below.
NOTE: The distance is in reciprocal space and you can easily notice that distance between the two bright spots is decreasing (while measuring the distant spots) instead of increasing because of reciprocal space.
Theory behind d value calculation:
- Selected Area Electron Diffraction (SAED) is very important technique to determine the crystal structure of any material. It is a complementary technique in Transmission Electron Microscope (TEM), in which the Electrons are diffracted at a selected area and bright spots with dark background are observed as a result of this.
Distance between two bright spots (D) = 2 × Radius of that circle
The distance is in reciprocal space so we take inverse to convert it into real space
Thus, the formula for Interplanar spacing (d):
Interplanar spacing (d) = 2 / Distance between two bright spots