The influence of defects on magnetic properties of fcc-Pu

TL;DR

This study investigates how vacancies and interstitial defects influence the magnetic properties of face-centered cubic plutonium using advanced computational methods, revealing defect-induced local magnetic moments consistent with experimental observations.

Contribution

It introduces a combined approach using molecular dynamics, MEAM, and LDA+U+SO to analyze defect effects on Pu magnetism, which is novel in this context.

Findings

Defects induce local magnetic moments in Pu

Magnetism results from disruption of spin-orbital and exchange balance

Results align with experimental data for annealed Pu

Abstract

The influence of vacancies and interstitial atoms on magnetism in Pu has been considered in frames of the Density Functional Theory (DFT). The relaxation of crystal structure arising due to different types of defects was calculated using the molecular dynamic method with modified embedded atom model (MEAM). The LDA+U+SO (Local Density Approximation with explicit inclusion of Coulomb and spin-orbital interactions) method in matrix invariant form was applied to describe correlation effects in Pu with these types of defects. The calculations show that both vacancies and interstitials give rise to local moments in $f$-shell of Pu in good agreement with experimental data for annealed Pu. Magnetism appears due to destroying of delicate balance between spin-orbital and exchange interactions.