Question

Difference between particle size and crystallite size

Answer 1

Grain size usually refers to the averagediameter of the individual crystal orientations found in poly-crystalline materials. ... Particle size refers to (again generally) the average diameterof a discrete piece of material, rather than a region in a material with adistinct crystal orientation.

Answer 2

Crystallites are coherent diffraction domains in X-ray diffraction. Grains are volumes, inside crystalline materials, with a specific orientation. Particles can be polycrystalline, single crystal or amorphous.