Dear Khwaja,

The spots are normally indicative of monocrystalline materials whereas the rings are due to the polycrystalline materials (also different crystallographic phases of material).

However, both represent diffraction patterns (means they are same) and used to calculate the d-spacings of different crystal planes of a material.

Note: these patterns are normally used as a complementary analysis (not very accurate sometimes and has limitations) to XRD analysis which is for sure more accurate and standard/ fundamental technique to find out the crystallographic information of any material.

I hope this helps

Wish you all the best

Rehan

Dear Khwaja,

You can see diffraction patterns as rings due to either polycrystalline materials or powder of monocrystalline (initially) materials.

Best regards,

Roman

Dear Khwaja,

Ring pattern is formed due to diffraction from polycrystalline material. This is because diffracting hkl planes are oriented randomly in all possible directions. However, If you select only few grains in your SAD apperture you will see spots in the form of rings because you do not have sufficient no of planes oriented in all directions.

Thanks

any specification about SiC; for example grain size, nanoinclusions or nanoparticles