Ion implantation in nanodiamonds: size effect and energy dependence

TL;DR

This study reveals a size-dependent radiation resistance in nanodiamonds, showing smaller particles are more susceptible to destruction by ion impacts due to extreme heating, with implications across nanotechnology, astrophysics, and environmental safety.

Contribution

It provides the first combined experimental and computational analysis of ion irradiation effects on nanodiamonds, highlighting a size effect on radiation resistance and the role of extreme heating.

Findings

Nanodiamonds larger than 8 nm resist radiation damage similarly to bulk diamond.

Nanodiamonds smaller than 8 nm can be destroyed by single ion impacts.

Extreme heating explains the vulnerability of small nanodiamonds to ion irradiation.

Abstract

Nanoparticles are ubiquitous in nature and are increasingly important for technology. They are subject to bombardment by ionizing radiation in a diverse range of environments. In particular, nanodiamonds represent a variety of nanoparticles of significant fundamental and applied interest. Here we present a combined experimental and computational study of the behaviour of nanodiamonds under irradiation by xenon ions. Unexpectedly, we observed a pronounced size effect on the radiation resistance of the nanodiamonds: particles larger than 8 nm behave similarly to macroscopic diamond (i.e. characterized by high radiation resistance) whereas smaller particles can be completely destroyed by a single impact from an ion in a defined energy range. This latter observation is explained by extreme heating of the nanodiamonds by the penetrating ion. The obtained results are not limited to nanodiamonds, making them of interest for several fields, putting constraints on processes for the controlled modification of nanodiamonds, on the survival of dust in astrophysical environments, and on the behaviour of actinides released from nuclear waste into the environment.