Cross-Linked Nano-onions of Carbon Nitride in the Solid Phase: Existence of a Novel C48N12 Aza-Fullerene

Lars Hultman, Linköpings universitet
Sven Stafström, Linköpings universitet
Zsolt Czigány, Linköpings universitet
Jörg Neidhardt, Linköpings universitet
Niklas Hellgren, University of Illinois at Urbana-Champaign
Ian F. Brunell, Linköpings universitet
Kazu Suenaga, Meijo University
Christian Colliex, Laboratoire de Physique des Solides

Abstract

We report a new fullerenelike material consisting of cross-linked nano-onions of C and N. Growth of the onion shells takes place atom by atom on a substrate surface and yields thin solid films during magnetron sputter deposition. Electron microscopy and energy loss spectroscopy show that the core shell contains up to 20 at. % N corresponding to C48N12 aza-fullerene composition. Nanoindentation of this nanostructured material gives high resilience with hardness 7 GPa, Young’s modulus 37 GPa, and complete elastic recovery after loading with 0.5 mN to a depth of 75 nm. Total energy calculations show the stability of C60-2nN2n aza-fullerenes and suggest the existence of a novel C48N12 molecule. © 2001 The American Physical Society.