Signatures of collective local and nanoscale distortions in diffraction experiments

TL;DR

This paper investigates how periodic and aperiodic distortions affect diffraction patterns in lattices, revealing that periodic distortions produce clear superlattice peaks while aperiodic ones cause subtle diffuse features.

Contribution

It provides a detailed analysis of how different types of distortions manifest in diffraction experiments, highlighting challenges in identifying aperiodic distortions.

Findings

Periodic distortions produce distinct superlattice peaks.

Aperiodic distortions result in subtle diffuse scattering features.

Identifying disorder signatures is difficult when periodicity is suppressed.

Abstract

The effects of periodic and aperiodic distortions on the structure factor and radial distribution function of single-component lattices are investigated. To this end, different kinds of distortions are applied to the otherwise perfect square lattice and the corresponding radial distribution function and structure factor for the resulting lattices are calculated. When the applied distortions have a periodic character, they are very easily recognized in the calculated structure factors as new superlattice peaks. However, when the periodicity of the distortions is suppressed the signatures of disorder only show up as smooth and subtle features on the diffuse part of the scattering, making it very difficult to identify the nature of the distortions present in the lattice. The implications of these results are discussed.