hi Ankit

yes, we can see the edge, screw and mixed dislocation by TEM/SAED.

edge dislocations are like zigzag lines.

Screw dislocations are a square or rectangular shape.

also, we can calculate dislocation density, dislocation cell and....

I suggest you Electron Microscopy and Analysis, Third Edition

By Peter J. Goodhew's book.

good luck

Thank you Dr. Ghanbarnezhad!!

Can you quote any literature available in which XRD is used to calculate approximate dislocation density?

For direct detection of dislocation in HRTEM images, you need to look at the images under very shallow angle. In the age of digitization, it means,  applying some distortion in digital image software. Please see our publication from 1988 (and maybe its citations):

https://www.researchgate.net/publication/279892998_Reproduction_of_electron_microscope_lattice_images_according_to_the_Scheimpflug_principle

Article Reproduction of electron microscope lattice images according...

dear Ankit

The dislocation density (δ) is the length of dislocation lines per unit volume of the crystal and could be calculated using Williamson-Smallman relation:

δ=1/D^2         D is the grain size that can be evaluated using Scherrer formula. For more detail. you can follow bellow reference:

D is the grain size that can be evaluated using Scherrer formula in xrd analysis software. 

 regards