Carbon whisker formation under fast particle irradiation

Abstract

The well known synthesis methods for carbon whiskers and carbon nano-tubes are dc arc discharge, laser ablation and catalytic processes. The configurations obtained are strongly influenced by the working conditions such as temperature, pressure and patterning substrates. In the present contribution, we report a simple process where carbon whiskers were produced by MeV D+ irradiated graphite. Scanning probe microscopy and X-ray diffraction methods were used to analyze the samples which consist of polished silicon used to collect the ejected matter. The results of the analysis revealed the presence of carbon nanoparticles embedded in a highly heated environment. SEM images clearly illustrate that these materials have highly complex structures. Initially, the carbon whiskers form well-separated spheroidal particles and subsequently transform into coral-like structures through step by step deposition. It is believed that the chaotic environment associated with the irradiation leads to the complex structures obtained. A scenario to explain such unexpected results is proposed.