Amorphous intergranular films act as ultra-efficient point defect sinks during collision cascades

TL;DR

This study uses atomistic simulations to compare ordered and amorphous intergranular films, revealing that amorphous films serve as highly efficient, unbiased sinks for radiation-induced point defects, enhancing radiation tolerance.

Contribution

It demonstrates that amorphous intergranular films outperform ordered boundaries as defect sinks, offering new insights for designing radiation-tolerant materials.

Findings

Amorphous films are ultra-efficient defect sinks.

Ordered boundaries absorb interstitials but not vacancies.

Amorphous films provide unbiased defect recombination pathways.

Abstract

Atomistic simulations are used to explore the effect of interfacial structure on residual radiation damage. Specifically, an ordered grain boundary is compared to a disordered amorphous intergranular film, to investigate how interface thickness and free volume impacts point defect recombination. The collision cascades induced by neutron bombardment are simulated and residual point defect populations are analyzed as a function of boundary type and primary knock on atom energy. While ordered grain boundaries easily absorb interstitials, these interfaces are inefficient vacancy sinks. Alternatively, amorphous intergranular films act as ultra-efficient, unbiased defect sinks, providing a path for the creation of radiation-tolerant materials.