Comparison of SIA Defect Morphologies from Different Interatomic Potentials for Collision Cascades in W

TL;DR

This study compares defect morphologies in collision cascades in tungsten simulated with three different interatomic potentials, revealing significant differences in predicted defect structures despite similar defect counts.

Contribution

It introduces an automated method for identifying defect morphologies and highlights the variability in defect structure predictions across different interatomic potentials.

Findings

Most defects form 1/2<111> dislocation loops

Disagreement in defect morphology predictions is greater than in defect counts

Various defect morphologies include rings, clusters, and mixed structures

Abstract

The morphology of defects formed in collision cascades is an essential aspect of the subsequent evolution of the microstructure. The morphological composition of a defect decides its stability, interaction, and migration properties. We compare the defect morphologies in the primary radiation damage caused by high energy collision cascades simulated using three different interatomic potentials in W. An automated method to identify morphologies of defects is used. While most defects form 1/2\3 dislocation loops, other specific morphologies include \1 dislocation loops, multiple loops clustered together, rings corresponding to C15 configuration and its constituent structures, and a combination of rings and dislocations. The analysis quantifies the distribution of defects among different morphologies and the size distribution of each morphology. We show that the disagreement between predictions of the different potentials regarding defect morphology is much stronger than the differences in predicted defect numbers.