Spatial ordering of nano-dislocation loops in ion-irradiated materials

TL;DR

This paper explains how nano-dislocation loops in ion-irradiated metals spontaneously form ordered patterns due to elastic interactions and Brownian motion, once a critical density is reached.

Contribution

It demonstrates that ordered dislocation loop structures can emerge spontaneously from elastic interactions and Brownian motion in irradiated metals.

Findings

Ordered loop patterns form above a critical density.

Elastic interactions bias the Brownian motion of loops.

Spontaneous pattern formation occurs due to local density thresholds.

Abstract

Defect microstructures formed in ion-irradiated metals, for example iron or tungsten, often exhibit patterns of spatially ordered nano-scale dislocation loops. We show that such ordered dislocation loop structures may form spontaneously as a result of Brownian motion of loops, biased by the angular-dependent elastic interaction between the loops. Patterns of spatially ordered loops form once the local density of loops produced by ion irradiation exceeds a critical threshold value.