Singh ed. This, in principle, allows the two effects to be distinguished. It is named after Paul Scherrer.

The concept of crystallinity can be used to collectively describe the effect of crystal size and imperfections on peak broadening. As the convolution of two Gaussians is just another Gaussian, we have that. For sufficiently large m the pair of planes are essentially uncorrelated, in the sense that the uncertainty in their relative positions is so large that it is comparable to the lattice spacing, a.

If all of these other contributions to the peak width were zero, then the peak width would be determined solely by the crystallite size and the Scherrer formula would apply. Redirected from Shape factor X-ray diffraction.