The crystallite size-disorder relationship based on the spiral paracrystal

A simple physical model of the relationship between crystallite size and di sorder for paracrystalline materials is presented, based on the spiral para crystal and distortion of the lattice cells. Simulations show that the mode l leads to relationships similar to the alpha* rule. Average crystallite si zes predicted by the model are in agreement with experimental data and also allow crystallite-size distributions to be proposed. The model provides a more satisfactory and complete explanation of this relationship than do cur rent descriptions.