  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.
