Difference between crystallite size and particle size
Answers
Explanation:
CRYSTALLITE and GRAIN are both SINGLE CRYSTALS.
A CRYSTALLITE is a single crystal in POWDER form.
A GRAIN is a single crystal within a BULK/THIN FILM form.
A PARTICLE is also thought of as an AGGLOMERATE. Small enough in size to not consider it as a bulk or thin film, but composed of 2 or more individual crystallites. Usually our group refers to a single body in a powder as a PARTICLE if we aren't sure about more specific details about its makeup.
When presenting SE micrographs in our group of our starting powders, we often initially report the particle size, because we can't accurately determine whether the particle is one crystal or composed of many compacted single crystals. Then after XRD or TEM analysis we can usually say whether each particle is an agglomerate composed of smaller crystallites (average crystallite size = X) or whether each particle is a single crystallite. And finally, when we present SE micrographs of fracture surfaces of our bulk samples, we definitely make references to average GRAIN size.
Hope this helps.