Estimating nanoparticle size from diffraction measurements

Nanometre-sized particles are of considerable current interest because of their special size-dependent physical properties. Debye-Scherrer diffraction patterns are often used to characterize samples, as well as to probe the structure of nanoparticles. Unfortunately, the well known 'Scherrer formula' is unreliable at estimating particle size, because the assumption of an underlying crystal structure (translational symmetry) is often invalid. A simple approach is presented here which takes the Fourier transform of a Debye-Scherrer diffraction pattern. The method works well on noisy data and when only a narrow range of scattering angles is available.