Nano-graphitization in amorphous carbon films via electron beam irradiation and the iron implantation

Nano-graphitization from amorphous carbon state is assisted by the electron beam irradiation. An inter-columnar region in the amorphous carbon films with low atomic and electron densities is controlled to have a graphitic structure by relatively low dose electron beam irradiation. This amorphous carbon - beam interaction generates a new type of carbon hybrids where the graphitic inter-columnar network is embedded into amorphous carbon columns. This hybrid film has an exotic mechanical and tribological response: extraordinary reversible deformability up to 8-10 % in normal strain, high wearing resistance and low friction at high normal pressure. A combination of iron-ion implantation with this electron irradiation provides us the other method of nano-graphitization process. An amorphous carbon film including the implanted iron atoms is chemically modified to have a columnar graphitic structure by the electron beam irradiation. In this post-implantation electron beam irradiation, the basic graphitic units with 1-2 nm in size are controlled to align vertically along the film thickness. This type of nano-graphitization has a strong dependency on the iron doses before electron beam irradiation. The above two types of nano-graphitization provides us a new tool to explore the functionalized structural thin films in application.