2006/01/31 by Yves Meheust, Yves Méheust, Kenneth D. Knudsen +5 · 1 citation
Materials Science · Physics and Astronomy · #Clay minerals and soil interactions #FOS: Physical sciences #Glass properties and applications #Materials Science (cond-mat.mtrl-sci) #Soft Condensed Matter (cond-mat.soft) #X-ray Diffraction in Crystallography #cond-mat.mtrl-sci #cond-mat.soft
paper · pdf · doi:10.48550/arxiv.cond-mat/0602007
11 pages, 10 figures. Attached figures are pixelized versions of the original vectorial figures
openalex publication_date 2006/01/31 · arxiv created 2006/02/01 · arxiv updated 2009/12/01 · openalex created_date 2022/10/06 · openalex updated_date 2026/07/28
The wide-angle scattering of X-rays by anisotropic powders of nano-layered\ncrystallites (nano-stacks) is addressed. Assuming that the orientation\ndistribution probability function f of the nano-stacks only depends on the\ndeviation of the crystallites' orientation from a fixed reference direction, we\nderive a relation providing f from the dependence of a given diffraction peak's\namplitude on the azimuthal angle. The method is applied to two systems of\nNa-fluorohectorite (NaFH) clay particles, using synchrotron radiation and a\nWAXS setup with a two-dimensional detector. In the first system, which consists\nof dry-pressed NaFH samples, the orientation distribution probability function\ncorresponds to a classical uniaxial nematic order. The second system is\nobserved in bundles of polarized NaFH particles in silicon oil; in this case,\nthe nanostacks have their directors on average in a plane normal to the\nreference direction, and f is a function of the angle between a nano-stack's\ndirector and that plane. In both cases, a suitable Maier-Saupe function is\nobtained for the distributions, and the reference direction is determined with\nrespect to the laboratory frame. The method only requires one scattering image.\nBesides, consistency can be checked by determining the orientation distribution\nfrom several diffraction peaks independently.\n