Nanometer-Thick Crystalline Carbon Films Having a Spinel Structure Grown on ZnO Substrates: Implications for New Ceramic–Carbon Composition

I developed a bottom-up process of crystal growth using a field emission (FE) electron beam without transfer of heat energy. In this study, highly crystalline single-walled carbon nanotubes were used as the FE electron source. Acetylene was irradiated with an electron beam of high-resolution energy emitted from the electron source. Then, zinc oxide (ZnO) was irradiated with the carbon-based ions dissociated from the acetylene and electron beam, which formed a nonequilibrium excitation reaction field. As a result, a crystalline carbon thin film with a spinel-like structure different from the structures of graphite and diamond was grown on the ZnO surface. It is considered that the carbon film can be formed on substrates with a periodic crystal structure, not only ZnO. I confirmed that a carbon film with a periodic crystal structure independent of the crystal structure of the underlying substrate was grown, which bridged with the substrate. Thus, I have established a technique of crystal bridging between a ceramic and carbon for the first time to the best of our knowledge.