Onion-like marbles and bats: new morphological forms of carbon

New spherical and bat-like carbon objects up to 1 mm in diameter and 3 mm in length have been produced in a radio-frequency furnace by evaporation and deposition of pure carbon. The objects form without the use of any catalyst. They have been characterised by scanning and high-resolution transmission electron microscopy, energy-dispersive microanalysis, X-ray diffraction, Raman, infrared and electron energy loss spectroscopy, magnetic, thermogravimetric and micro-hardness measurements. The objects consist of nearly perfect concentric shells, scaling down to nanometer dimensions in the centre. Their properties reveal similarities to both graphite and carbon nanotubes.