Extrinsic faulting in $3C$ close packed crystal structures: Computational mechanics analysis

TL;DR

This paper applies computational mechanics to analyze extrinsic faulting in 3C close packed crystal structures, deriving analytical expressions for disorder metrics and comparing faulting types through an psilon-machine framework.

Contribution

It introduces a computational mechanics approach to quantify extrinsic faulting, providing analytical tools and comparisons with other faulting mechanisms.

Findings

Derived expressions for statistical complexity, entropy density, and excess entropy.

Presented an psilon-machine model of extrinsic faulting.

Analyzed the impact of faulting on diffraction patterns.

Abstract

Extrinsic faulting has been discussed previously within the so called difference method and random walk calculation. In this contribution is revisited under the framework of computational mechanics, which allows to derive expressions for the statistical complexity, entropy density and excess entropy as a function of faulting probability. The approach allows to compare the disordering process of extrinsic fault with other faulting types. The {\epsilon}-machine description of the faulting mechanics is presented. Several useful analytical expressions such as probability of consecutive symbols in the Ha\"agg coding is presented, as well as hexagonality. The analytical expression for the pairwise correlation function of the layers is derived and compared to results previously reported. The effect of faulting on the interference function is discussed as related to the diffraction pattern.