Nano-structure and property transformations of carbon systems under γ-ray irradiation: a review

Carbon-based materials have been used quite successfully for decades within industry sectors. Especially, the application of them in the field of aerospace has been paid lots of attention. The severe environment such as γ-rays in space, which may give rise to the formation of atomic defects, may deteriorate the performance of carbon-based devices significantly. However, in addition to the well-known cases of destroying the properties of carbon systems, recent experiments show that γ-ray irradiation can also be employed as an attractive tool for the fabrication, modification and manipulation of carbon materials. In this article, we briefly review the recent progress in our understanding of γ-ray irradiation-induced phenomena in some carbon systems with experimental results and theoretical analysis. Particular emphasis is put on the discussion of the effects of γ-rays on nanostructure and morphology of carbon fibers, graphite, carbon nanotubes, graphene and diamond, as well as the methods for tailoring their mechanical, chemical and electronic properties. Finally, we attempt to identify the future directions in which the irradiation-induced modification field is likely to develop.