Sunday, 1 January 2017

SAED d value and XRD Peak Position calculator

SAED (Selected Area Electron Diffraction) d value and XRD Peak Position calculator

Distance between 2 bright spots (nm)


d value (nm)

XRD Peak Position (2θ)

Calculation Tutorial:
STEP1: Take the raw image of Selected Area Electron Diffraction (SAED) from Transmission Electron Microscope (TEM)

STEP2: Now enter the distance (nm) 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. SAED d value calculation

NOTE: XRD peak position is calculated by taking Laser wavelength as 0.15418 and n value as 1. The distance is in reciprocal space. We have made the calculator such that if you measure the distance directly from 1/nm scale (as shown in image) it would give you the exact d value results.

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