Structural hierarchy of nanocarbon in copper covetics

We prepared 0.4 wt. % carbon infused copper (i.e., copper covetic, CuCv) by electron-beam melting and deposited approximate to 18 nm-thick films of the CuCv on a substrate by electron-beam evaporation. Helium ion microscopy (HIM) and scanning transmission electron microscopy (STEM) were used to study the characteristics of the carbon nanostructure in the CuCv bulk and thin films. HIM observation of the fracture and ion-polished surface of bulk CuCv revealed ripple structures that are associated with carbon nanoribbons formed in the copper matrix. STEM high angle annular dark field imaging and energy dispersive spectroscopy mapping indicated that carbon nanoparticles and carbon-rich pathways are interconnected to form a carbon-rich network in the CuCv films. High-resolution transmission electron microscopy and STEM electron energy loss spectroscopy suggest that the carbon nanoparticles are composed of highly distorted graphenic carbon sheets that are bonded to the copper matrix and likely provide means for superior electrical and thermal conduction. In this letter, we report structural hierarchy and representations of carbon nanostructures in copper covetics at different scales from a few micrometers to subnanometers. Published by AIP Publishing.