Electronic effects on the radiation damage in high-entropy alloys

TL;DR

This study investigates how electronic effects influence radiation damage in high-entropy alloys, revealing that electron-phonon interactions significantly affect defect formation and suggesting composition optimization for enhanced radiation resistance.

Contribution

The paper provides a systematic first-principles analysis of electronic properties in HEAs and demonstrates their critical role in defect dynamics during radiation events, highlighting new pathways for alloy design.

Findings

Electron-phonon coupling dissipates kinetic energy during defect formation.

Including lighter elements increases electron-phonon coupling, improving radiation resistance.

Electronic effects outweigh elastic distortion effects in defect evolution.

Abstract

High-entropy alloys (HEAs) are exceptional candidates for radiation-resistant materials due to their complex local chemical environment and slow defect migration. Despite commonly overlooked, electronic effects on defects evolution in radiation environments also play a crucial role by dissipating excess energy through electron-phonon coupling and electronic heat conduction during cascade events. We present a systematic study on electronic properties in random-solid solutions (RSS) in four and five principal elements HEAs and their effect on defect formation, clustering, and recombination. Electronic properties, including electron-phonon coupling factor, the electronic specific heat, and the electronic thermal conductivity, are computed within first-principles calculations. Using the two-temperature molecular dynamics simulations, we show that the electron-phonon coupling factor and electronic specific heat play a critical role in Frenkel pairs formation. Specifically, the electron-phonon coupling factor quickly dissipates the kinetic energy during primary knock-on atom events via plasmon excitations and is subsequently dissipated via the free-electrons conduction. We show that these effects are more critical than the elastic distortion effects produced by the atomic mismatch. Of tremendous interest, we show that including lighter elements helps to increase the electron-phonon coupling factor, suggesting the possibility to improve radiation resistance in HEA through optimal composition.