Discovering Planar Disorder in Close-Packed Structures from X-Ray Diffraction: Beyond the Fault Model

TL;DR

This paper introduces a comprehensive method for analyzing planar disorder in close-packed structures from X-ray diffraction data, surpassing traditional fault models by providing more accurate structural descriptions.

Contribution

The authors develop a novel statistical approach that captures the full disorder in CPSs and determines the minimal effective memory length of stacking sequences, improving upon existing fault models.

Findings

The method accurately characterizes disorder in zinc sulphide diffraction spectra.

In simple cases, the approach reduces to the fault model, validating its consistency.

In complex cases, it offers a more precise structural description.

Abstract

We solve a longstanding problem--determining structural information for disordered materials from their diffraction spectra--for the case of planar disorder in close-packed structures (CPSs). Our solution offers the most complete possible statistical description of the disorder, and, from it, we find the minimum effective memory length of disordered stacking sequences. We also compare our model of disorder with the so-called fault model (FM) and demonstrate that in simple cases our approach reduces to the FM, but in cases that are more complex it provides a general and more accurate structural description than the FM. We demonstrate our technique on two previously published zinc sulphide diffraction spectra.