Vacancy clustering in zirconium: an atomic scale study

TL;DR

This study investigates vacancy cluster stability in zirconium using atomic-scale modeling, combining density functional theory and empirical potentials to understand defect energetics and loop formation.

Contribution

It introduces a multiscale modeling approach that combines ab initio and empirical data to analyze vacancy clusters and their thermodynamic properties in zirconium.

Findings

Vacancy-vacancy interactions influence cluster stability.

Extended vacancy clusters can be described by continuous defect laws.

Thermodynamic properties explain the ease of loop formation.

Abstract

The stability properties of vacancy clusters in hexagonal close-packed Zr, cavities and dislocation loops, are investigated at the atomic scale, with a modeling approach based on density functional theory and empirical potentials. Considering the vacancy-vacancy interactions and the stability of small vacancy clusters, we establish how to build the larger clusters. The study of extended vacancy clusters is then performed using continuous laws for defect energetics. Once validated with an empirical potential, these laws are parameterized with ab initio data. Our work shows that the easy formation of loops can be explained by their thermodynamic properties.