Experimental and Theoretical Aspects of the Fragmentation of Carbon's Single and Multi-Walled Nanotubes

TL;DR

This paper investigates how energetic ion irradiation causes fragmentation of carbon nanotubes, combining experimental results with theoretical models and information theory to understand the underlying mechanisms.

Contribution

It introduces an integrated approach using thermal and information-theoretic models to distinguish collision cascade and thermal spike effects in nanotube fragmentation.

Findings

Experimental data supports the models of fragmentation mechanisms.

Shannon entropy and fractal dimension characterize sputtered species distributions.

Kullback-Leibler divergence identifies emission mechanism diversity.

Abstract

Energetic ion irradiation is an effective method for studying how single and multi-shelled carbon nanotubes break apart. The energy from ions is dissipated through both linear and nonlinear processes in the nanotubes, leading to defect formation. Fragmentation occurs via atomic collision cascades and thermal spikes, each described by different theoretical models. Experiments with Cs-irradiated nanotubes support these models, and an information-theoretic approach further explains the fragmentation mechanisms. Sputtered species yield probability distributions, which are analyzed using Shannon entropy and fractal dimension to assess spatial characteristics. Kullback-Leibler divergence helps identify the diversity of emission mechanisms. Together, thermal and information-theoretic models clarify and distinguish the roles of collision cascades and thermal spikes in nanotube fragmentation.