Estimating nanoparticle size from diffraction measurements

Nanometre-sized particles are of considerable current interest because of t heir special size-dependent physical properties. Debye-Scherrer diffraction patterns are often used to characterize samples, as well as to probe the s tructure of nanoparticles. Unfortunately, the well known 'Scherrer formula' is unreliable at estimating particle size, because the assumption of an un derlying crystal structure (translational symmetry) is often invalid. A sim ple 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.