Dear Guarav,

The principle of crystallite size measurements by x-ray diffraction is based upon the fact that the Fourier transform of different size crystallites varies inversely with the size of the crystallite. X-rays in the 0.15 nm range can measure crystallite sizes from approximately 2nm to 500nm.

The crystallite size is the average size of a coherent scattering domain (perfect arrangement of unit cells or perfect crystal).

In most cases the crystals observed in SEM are not "perfect" and will not lead to coherent scattering. Meaning, one crystal can consist of multiple crystallites. Also, in SEM investigations people often speak about crystal size but are in fact describing grain size.

Regards,

Sebastian

I agree with this comment.

"In most cases the crystals observed in SEM are not "perfect" and will not lead to coherent scattering. Meaning, one crystal can sonsist of multiple crystallites. Also, in SEM investigations people often speak about crystal size but are in fact describing grain size." Sebastian Reinhold Klaus

Alan F Rawle

Edited the text accordingly

Sebastian Reinhold Klaus

Thank you.

Dear Dr. Sebastian Reinhold Klaus

Thank you for such nice explanation. it really helped me with my issue.

Thanks,

Gaurav Vyas.