Optical transforms of disordered systems displaying diffuse intensity loci

Abstract

A method is described of synthesizing a real-space distribution of scattering points which will give rise to virtually any required diffraction pattern. The distribution may be used in the form of an optical diffraction screen to give an immediate visual check on both the real-space and reciprocal-space distributions. The method is applied to two examples which exhibit electron diffraction patterns with diffuse intensity distributed in the form of complex loci in reciprocal space: certain transition-metal niobium sulfide intercalates in which ordering of metal ions and vacancies occurs; and the high-temperature phase of 1T tantalum disulfide in which phenomena due to charge-density waves (CDW) and accompanying periodic lattice distortions (PLD) are observed. It is shown how useful statistical information concerning the local ordering may be obtained from the resulting lattice realizations. Show more