A New Type of Carbon Nanostructure Formed Within a Metal-Matrix

L. Salamanca-Riba, A. Herzing, A. Mansour, A. Hall, D.R. Forrest, M. LeMieux, J. Shugart
University of Maryland, US

Keywords: nanocarbon, nanostructures, electron microscopy, structure

Summary:

Recent advances in nanomanufacturing have made it possible for large amounts (up to 6 wt.%) of carbon to be incorporated as nanoscale carbon during a reaction process in molten metals. These materials are called “covetics”. The carbon is highly stable and remains dispersed after remelting and resolidification. The carbon incorporates into the crystal structure of the metal and has an effect on several of the properties of the material. We have performed XPS, XAS, SEM, TEM, STEM/EELS, and Helium Ion Microscopy to investigate the structure of covetics. Carbon is seen in the form of nanoparticles 5-200 nm in diameter. There is also evidence for finer, ordered carbon structures within the metal lattice ranging in size from 20 to 200 nm. TEM images show incorporation of C in the lattice structure of the host metal. Cu covetic shows a modulation of ~1.2 nm. Ag covetic shows what seems to be alternating layers of graphene embedded in between the (111) planes of Ag. The C-K edge EELS spectrum has closer shape to that from single wall carbon nanotubes than for graphite, or diamond. A detailed investigation of the structure of these novel materials will be presented.